A Guide to Implementing the Theory of Constraints (TOC)

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Preface

Introduction

Contents

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Healthcare

 

Measurements

People

Process of Change

Agreement to Change

Evaluating Change

Leadership & Learning

 


Evaluating Change

When we set out to implement change we must remember that there are 3 possible outcomes.  These outcomes are;

(1)  A change which is a significant improvement.

(2)  A change which is neither a significant improvement nor a significant decline.

(3)  A change which is a significant decline.

Naturally enough, it is the first option that we are really seeking.  We want to make a difference, and we want that difference to be manifestly positive.  In order to do so, we must make decisions prior to carrying out the desired actions, and to be certain in the knowledge that those decisions will deliver the necessary results that we seek.

How we evaluate the improvement will depend upon the goal of the system.  If the goal is a monetary one, then the evaluation is relatively straightforward.  And that is what we will concentrate on here.  In not-for-profit, or more correctly, for-cause situations how we evaluate an improvement is a little more involved; however, if you look at the argument for healthcare (supply chain section) then you will find some good indications of how this can be achieved.

We are evaluating changes within the context of the whole system – or the system as a whole.  We are not interested in local improvements that do not have system-wide impact.  How, then, would we judge an impact in such a circumstance?  We need a context.  We already have one, let’s revisit it.

 
The Context

On the measurements page we derived our rules of engagement.  These tell us how to define the entity that we want to improve.  We define the boundaries, the goal, the necessary conditions, and the fundamental measurements.  Without these, we do not have a context within which to evaluate change.  Moreover, this forces us to determine what it is that constrains us from moving towards our goal; we have to define the role of the constraints.

The constraints are central to our ability to move forward.  In order to define the role of the constraints we need to invoke our plan of attack, the one we developed on the process of change page.  Of course, our plan of attack is Goldratt’s focusing process.  The second step of this plan, where we decide how to exploit the constraints, is the step that provides commonality between these two schemes.

We have previously summarized the relationship between the rules of engagement and the plan of attack as follows;

Rules of Engagement

Plan of Attack

(1)  Define the system.

 

(2)  Define the goal of the system.

 

(3)  Define the necessary conditions.

 

(4)  Define the fundamental measurements.

(1)  Identify the system’s constraints.

(5)  Define the role of the constraints.

(2)  Decide how to Exploit the system’s constraints.

 

(3)  Subordinate everything else to the above decisions.

 

(4)  Elevate the system’s constraints.

 

(5)  Go Back - Don’t Stop.

In order for a change to be an improvement it must either have a direct positive effect upon the current exploitation or elevation of the system’s constraints, or an indirect effect via improved subordination which in-turn ought to improve the exploitation or elevation, either now or in the future. 

To quantify these effects we must return to our fundamental measurements.

 
The Fundamental Measurements

In the first page, the page on measurements, we briefly introduced the concepts of; throughput, inventory/investment, and operating expense; a triumvirate set of measures for quantifying effects in Theory of Constraints.

Throughput as you may remember was described as;

Throughput  =  Sales - Totally Variable Costs

From this we came to define our net profit as;

Net Profit  =  Throughput - Operating Expense

And return-on-investment is;

It is through these 3 fundamental measures of; Throughput, Inventory/Investment, Operating Expense, and the two basic relationships of net profit and return-on-investment that we are able to evaluate change.

The reason that we can do so much with so little is because of the fundamental relationships that exist between each measure.  They are systemic.

Let’s try to reinforce the fundamental and systemic nature of these measures by way of analogy.  By this means we will be in a far stronger position to understand change and how to evaluate it.

The analogy is a see-saw.

 
The See-Saw Analogy

A see-saw!  How does the evaluation of change relate to a see-saw?  Well, let’s have a look.

Let’s draw a simple see-saw as a start.

In this simple example a lever – a plank – sits centered exactly across a fulcrum, therefore we have 1/2 of the plank on one side and 1/2 of the plank on the other.  We can quite easily balance two equal masses at either end of the plank.

The two equal masses – “people” are located equidistant from the mid-point of the plank, so let’s label that.

The mid-point is also the point of balance, so let’s add that as well.

Now; what if we move the plank along a bit?  What if we move the plank along so that it is now half way closer towards one end than the other, so that we have 3/4’s of the plank on one side and 1/4 on the other?  What would be the effect?

Let’s see.

The effect is that we can now balance 3 times the mass on the shorter end.  In effect we have gained some leverage.  And for the purists amongst us we have balanced the 3 masses over a pivot under the middle person on a secondary upper plank.  Both planks have been tested by applied mathematicians and deemed to have “no real mass,” so for the purposes of this analogy we can ignore the mass of the planks themselves.  It is only the leveraging ability that we are interested in.

Can we use this simple analogy of a see-saw for evaluating internal management decisions, change in other words?  In terms of physical aspects it is apparent that we seek to leverage inputs of some kind via a process of some sort in order to produce outputs.  In fact, the process does not exist in isolation but rather it exists in conjunction with a set of operating assumptions; the things that we call policies.  How then would this look using our model?  Let’s see.

Does this reflect reality?  I think so.  We use our physical process in conjunction with our operating policies to produce more output than input.

How then would our model look in terms of financial aspects?  In the terms of financial aspects it is apparent that we seek to leverage expenditure via investment to produce income.  Once again the investment does not exist in isolation but rather it exists in conjunction with a set of working assumptions; policies once again.  Let’s see how this looks.

When we buy a business (an investment) it consumes cash (expenditure) and produces even more cash (income) as a result.  We definitely leverage our expenditure via our investment.  This is why some businesses are described as “cash cows” and, equally, why some are not.  Of course the physical aspects and the financial aspects are just different views of the same system, simplified here by a one to one correspondence between physical and financial units – the masses that sit on the plank.

We need to ask then; will this simple analogy, a see-saw, also work as a description for evaluating change in Theory of Constraints?  Well, I think so, so let’s try.

From our cash expenditure we take all raw material or 1:1 variable costs out of contention to obtain our operating expense – that is, after all, how we define operating expense.  From our income we also take all raw material or 1:1 variable costs out of contention to obtain our throughput – again, this is how we define throughput.  The 1:1 variable costs are simply equal flows into the system as raw material and inputs, and equal flows out of the system as sales.  In essence then, we leverage our operating expense via our capital investment to produce throughput.  And, yes, we still have policies to guide us.

It seems then, that our analogy will hold for our fundamental measures.  Great.

Any change in throughput, or operating expense may change the balance of our system.  Do you agree?  Our analogy shows the interrelationships between these various aspects.

Do you want to push the analogy a little bit further?  What is our profit then?

Let’s have a look.

Throughput minus operating expense equals profit.  So now we know that our analogy will accommodate our definition of profit as well (call it operating surplus if you prefer).  So, in reality, we leverage our operating expense via our investment to produce a profit.

What about the balance point then?

The balance point is a measure of the leveragability that we have attained.  The greater the leveragability, the further the balance point will move along the plank towards the right in our model.

We know the location of the balance point, but this begs a question.  What is the fulcrum that we leverage across?

Let’s have a look.

The fulcrum is not a physical constraint, the fulcrum is time.  Take a breath; stop and think about it for a moment.

I know that all too often we loosely talk about leveraging the constraint – we have used that language throughout these webpages and it is probably ingrained.  But in reality we are leveraging our entire system over the fulcrum – time – and the only way that we can do that, either literally or metaphorically, is via the constraint.  So we leverage the system via the constraint for a given unit of time.

So, yet another question; what exactly is the constraint in our analogy then?

Well, it must be the seating capacity, or the seating spacing – different ways of saying the same thing.  Ultimately it is the length of the secondary plank which constitutes the constraint in our see-saw analogy.

Now that we have identified the constraint, how can we get more of this limiting factor?  How in our metaphor can we get more people sitting balanced on the right-hand side?  How can we improve the Throughput?  How can we improve the profit?  There are two answers to these questions, and they are that we can increase the productivity, and/or we can increase the production.  We need to tease these two strands apart in order to better understand each of them.  Let’s do that.

 
Productivity & Production

Making a distinction between productivity and production is important in understanding how to most effectively drive improvement, and such a distinction is also useful in developing our understanding of the dynamics of exploitation, subordination, and elevation.  Production is the simpler, and certainly more familiar of the two concepts, so let’s start with that.

Essentially any increase in production is a pro rata increase in both inputs (operating expense), and outputs (Throughput).  Let’s investigate this with our see-saw analogy.

Let’s start again with our original model with a balance point located 3/4 of the way along the plank.

Without moving the balance point we could double our throughput by doubling our operating expense.  Let’s do that.

Two units of operating expense now balance 6 units of throughput.  The initial ratio is preserved.  In fact, by doubling operating expense and doubling throughput, we must also double the profit at the same time.

In effect the increase in inputs (operating expense) drives the increase in outputs (throughput).  The leveragability of the system remains unchanged.  The fact that the balance point doesn’t change is a simple indication that we are dealing with increases in production rather than productivity.  In effect we elevate the existing system by bringing something new into the system – in this case new and additional expenditure as operating expense.  Of course there must be latent capability to do this.  In the real world this might equate to an additional shift as a simple example.

Increasing production, seductive as it is – after all this is what almost everybody else does – is nowhere near as sexy as improving productivity per se.  Moreover, if we were to go around doing what everyone else does then there is hardly any strategic advantage to be had at all.  So let’s investigate the impact of improving productivity; many people talk about increasing productivity but few actually manage to do it.  Doing it is not at all difficult if we have focus.

Rather than settling for a pro rata increase in both operating expense and throughput, which means constant productivity – only more of it, we actively seek to decouple throughput from operating expense, which in-turn means increased productivity.  Throughput should increase and ideally operating expense should remain static or even decrease; something other than additional operating expense drives the additional throughput.  It is the leveraging of the entire system via the constraint’s throughput relative to the fulcrum, time, that drives the additional throughput.  Let’s show this by example.

Let’s start again with our original model with a 3:1 ratio.

This time, instead of increasing operating expense, we will move the lever, and thus the balance point, even further to the left while maintaining the same operating expense.  Let’s halve the remaining distance between the fulcrum and the right-hand side so that we now have 7/8’s of the lever on one side and 1/8 on the other.  What do we get?  Let’s see.

Our single unit on the left, our operating expense, can now leverage against 7 units of throughput on the right.  Previously, by increasing production, we obtained 6 units of throughput for the cost of 2 units of operating expense.  Now, by increasing productivity, we get 7 units of throughput for the cost of just 1 unit of operating expense.  Our productivity has substantially increased and our throughput has become decoupled from the operating expense.

An increase in productivity will in-turn substantially increase profit.  Let’s have a look at that.

For no change in operating expense, but with better leverage of the existing system we can triple our profit!  If tripling the profit sounds fanciful, believe me, it is not!

We obtain better leverage by better exploitation of the constraint (the secondary plank becomes longer) and by better subordination of the non-constraints.  Often the simplest way to obtain an increase in leverage is to remove or modify some current policy.  Organizations abound with policy; that is, after all, one way in which to standardize matters, and without standardization there can be no base from which to improve.  But what if the standardization causes us to stagnate instead of improve?  Policy also allows us to react quickly without reinventing the wheel each time.  But what if we no longer need a particular reaction and yet we still have the policy?  Removal of outdated or inappropriate policy unblocks access to current capacity and increases productivity.

Now, if we are still bored with our newfound increase in productivity, then we can still increase our production after we have increased our productivity – given that our capacity allows for it.  It pays in more ways than one to increase relative productivity first, and then absolute production second, rather than the other way around.  Always aim for capability before capacity.

That is why the 5 focusing steps; our plan of attack goes; identify, exploit/subordinate, elevate – in that order.  Most firms go; identify, elevate – every time.  In fact that is unfair, most firms miss the identification stage and have a scatter gun approach of; elevate, elevate, elevate.  Hardly a wise use of cash, and a total absence of any systematic decision analysis.

In reality, often both productivity and production are inexorably mixed together, but we need to understand the dynamics of each component if we are to better understand how to correctly influence the whole – even if later on we can’t so neatly break the whole back into constituent parts as we have here.

It is apparent from the logic of this discussion that as the lever moves with respect to the fulcrum; the productivity, throughput, and hence profit, should trend towards infinity.  But we are getting ahead of ourselves.  None of us are making infinite profits yet (or if we are, then we certainly haven’t told Inland Revenue about it).  So, this begs a question.

Why aren’t we making infinite profits yet?  Well, a valid reason might be a finite capacity or capability of the current constraint; we are unable to move the balance point any closer to the end of the lever.  We can neither exploit the constraint nor subordinate the system any further, even though the demand is there?  What shall we do?

Well, why don’t we make the lever even longer?  Let’s have a look at a new aspect; investment.

 
The Effect Of A Financial Investment

In our analogy additional investment means that our lever becomes a little longer.  The effect of the investment in this instance is to both exploit & elevate the existing constraint or to better subordinate the non-constraints which in-turn exploits the constraint.  Let’s work from our current state where we have 7/8’s of the lever on one side and 1/8 on the other.  Here is our starting point.

Let’s have a look at an investment which improves the physical capacity or capability of our lever by an additional 2/8’s to meet a very real and existing, but previously unrealized, demand.

Our 8/8’s plank now becomes 10/8’s long, 9/8’s one on side of the fulcrum and 1/8 on the other side.  Now our unchanged operating expense can leverage against even more throughput than before.  We can produce an additional two units taking the total up to 9 units altogether!

The effect of the investment is to increase the physical leveragability of the system even though the absolute position of the balance point remains static.  Effectively we have increased the productivity of the system by capital investment.  This is interesting (to me).  Here we have both elevation (cash from outside the system was brought inside – even though it is not an increase in operating expense) and exploitation (the absolute position of the balance point did not change, but the position relative to the whole plank did change).  Alright, maybe that is pushing our metaphor about as far as it should go at the moment.

 
See-Saws & Equations

Let’s now return to the formulae that express the reality of these simple diagrams to further evaluate the situation.  We introduced 3 equations in the section on fundamental measurements, let’s repeat two of them here, one for throughput and one for profit (or operating surplus);

Throughput  =  Sales - Totally Variable Costs

and

Net Profit  =  Throughput - Operating Expense

Of course we can combine these into one statement

Net Profit  =  Sales - Totally Variable Costs - Operating Expense

However, let’s confine ourselves to the simpler version

Net Profit  =  Throughput - Operating Expense

And let’s compare this directly with the simplest of our see-saw analogies.  Here is the analogy.

Applying the equation we get,

Net Profit  =  3 Units of Throughput - 1 Unit of Operating Expense  =  2 Units

Just as we drew it,

And this brings us to an interesting “yes, but…”

 
How Do We Express The Fulcrum?

We can see that the fulcrum is represented in the diagrams and we can see that its positioning under the balance point is critical, and we know that it represents time, yet it seems to disappear from our equations.  Let’s clarify this issue.

The fulcrum is time – the one thing we don’t seem to be able to generate any additional quantity of, and time is present in our equations, but we seem to have been a little lax in making it explicit.  Really our equations should read as follows.

Throughput should be;

Net Profit should be;

So, it appears that the fulcrum is indeed there, we just didn’t make it clear enough.

And one again, if we combine these equations we get;

Thus, for any historic period it is easy to determine profit.  We just sum all of the sales and subtract all of the totally variable costs and then subtract all of the other costs that vary over the period – our operating expense.  There are no awards for doing this.  It’s historic; what is done is done.

We are more interested in evaluating change before we make the change.  We want to know the outcome of a potential decision before we take action to implement it as an actual decision.  And for this we need some critical information.

We need to be able to determine the Throughput through a unit of constraint capacity in relation to time.

This is the major decision analysis that we make.  We need to examine this in detail.

 
Determining Throughput At The Constraint

Let’s return to our original case for a moment.

When we looked at the physical aspects we found that we had 3 units of output and they each were equal to the weight of one adult.  In other words there is a one to one correspondence between the number of units and the physical output of the system.

Upon the improved leverage of the example above we found the following;

There is still a one to one correspondence between number of units of output and their weight.

But equally, we might also have found this;

3 of the adults have been substituted for by “children.”  We still have 7 units of output in total but the weight is now “lite.”

If we substituted children for all of the adults we could even have found this;

It appears that, within this analogy, the number of units of output from the constraint and the weight of that output no longer shares a one to one correspondence.  In every case we are making more output now than in the case of the 3 adult units that we began with, in fact in each case the number of units is 7, but the increase in weight is much less.

How can we know ahead of time what the outcome of these types of substitutions will be?  Graphically it seem obvious, we need to know the output value, the weight, for each type of output in this system relative to the unit constraint capacity.

Let’s show this.

At the constraint, one type of output unit, let’s call this a child, is half the weight of another type of output unit which we have called an adult.  We can directly compare one output with another by normalizing them at the constraint over some measure of time.

It is a simple step to move our analogy from output to throughput so that we can evaluate the financial aspects.  Let’s have a look.

 At the constraint, one type of throughput unit, a child, generates half the value of another type of throughput unit, an adult.  We can directly compare the throughput of one with another by normalizing them at the constraint over some measure of time.

 
T/cu Short-hand And Other Expressions of Constraint Units

We have produced a normalized throughput per unit of output as viewed from the perspective of the constraint.  But, we have nearly lost sight of our fulcrum (again).  What has happened to our measure of time?

Mention was made of the short-hand expression “T/cu” or Throughput per constraint unit earlier.  This short-hand is partially responsible for the apparent lack of time.  It is there, however.  The full expression should be “throughput per constraint unit per unit time,” or T/cu/t.

In our simple analogy our constraint unit is seating, and thus we would evaluate Throughput as Throughput $ per seat per ride.  “Seat” is the constraint unit, “ride” is the expression for time.

Let’s look at a few other general cases.  What about a sunshine factory?  And by that I mean an outdoor agricultural or horticultural enterprise.  The constraint unit here is available productive area, and the decision analysis becomes Throughput $ per acre or hectare per season or per year (T$/hectare/year).

What about an indoor retail operation?  Something that doesn’t make anything; just buys and sells.  The constraint unit here is again productive area, if might be square meters or square feet of floor space, or square meters or square feet of shelf space if there is a vertical component as well, and the decision analysis becomes Throughput $ per square meter per week or per month depending on the rate of turnover (T$/m2/week).  Supermarkets tend to use linear meters of “facing” assuming that we buy in proportion to what we see.  If the facing all has the same volume stacked behind it, then there would seem to be little difference in the various units.

Larger items in a sales system where a sale is concluded after a sales process, then the constraint should be the number of contact sales hours that the sales people have.  The decision analysis becomes Throughput $ per sales person per hour or day (T$/sales person/hour).

In manufacturing the constraint is most usually a machine or group of machines and this is the constraint unit, the unit of time is most commonly minutes because manufacturing steps are more commonly completed within minutes or hours rather than days.  The throughput decision analysis becomes Throughput $ per machine per minute (T$/machine/minute).  Some examples that I know of are people-paced rather than machine-paced and the throughput decision analysis becomes Throughput $ per man per hour (T$/man/hour).

What then of projects?  The constraint is the number of resources working on the critical chain.  The Throughput decision analysis becomes Throughput $ per critical chain person per project week or month (T$/critical chain person/month).

Remember these are decision analyses; the analysis of various choices before we embark on a decision.  Once we have made a commitment to the customer we can’t internally re-prioritize according these values.

With this new information under our belt, now, at least, we can predict the Throughput for the following case before we actually do it.

We have substituted 3 by $1 units of throughput with 3 by $0.5 units of throughput.  The total throughput is therefore $5.5, and not the $7 that we could potentially achieve.  The profit is now $4.5  and not $6 as before.  That’s $4.5 total profit per ride.

What about the other case?

Here we substituted 7 by $1 units of throughput with 7 by $0.5 units of throughput.  The total throughput is therefore $3.5, and not the $7 that we could potentially achieve.  This is still more than the $3 that we started with before we leveraged the system – but not by very much.  The profit is now $2.5, half a unit better than the $2 we had before,  but way short of the potential of $6 per ride.

Graphically this is just plain obvious, we can see, and we know from our own direct experience with see-saws.  But trust me, in most organizational systems this is anything but clear, and one good reason for this is that almost no one in most organizations has ever considered this before.

“We have to evaluate the impact, not of a product, but of a decision.  This evaluation must be done through the impact on the system’s constraints.  That’s why identifying the constraints is always the first step (1).”

We have to know where the constraint, is; and we have to know the Throughput value of the output with respect to that constraint.

So, anyone can work out the Throughput retrospectively for any period.  No one can evaluate the Throughput proactively for the current or future periods without explicit knowledge of the Throughput value generated with respect to the constraint.  In some instances this might be quite obvious; most often, however, it is not.  And when it is done there are most often some surprises in the relative ranking of the outputs.

This brings us to a very important point.

 
Change Just One Important Thing!

We all know from our own personal experiences with see-saws, that if we change just one important thing then the whole balance may change.  If we move the plank a little, or if someone gets on, or if someone gets off, or even it someone changes ends, then, so too, does the balance.  And so too, with our system under investigation.

We didn’t know previously that once we elevated this system that children might get on, or that adults might get off.  But every time we prepare to change the constraint that is exactly what we must evaluate for.  We must evaluate for the new mix that could arise.  If we think that we will elevate a constraint to the extent that we will break it (and thus a new constraint presents itself) then the unit throughput values, and thus the individual ranking, may also change and therefore maybe also our tactics for exploitation will change as well.

We must predict the outcome ahead of implementing the decision.  “You see, in the ‘cost world’ almost everything is important, thus changing one or two things doesn’t change the total picture much.  But this is not the case in the ‘throughput world.’  Here, very few things are really important.  Change one important thing and you must re-evaluate the entire situation (2).”

 
Evaluating Change – Internal Constraints

In internally constrained systems we can not satisfy market demand.  We can show this with our analogy?  Of course we can.  The beam is full, we could get other people on, if only they would fit.

Moreover, it implies that we may have a choice.  For instance we may choose to only allow high throughput members onto the see-saw as above.  In that case we may choose to avoid the following.  However, we may also choose to encourage it.

I say “may” because this depends upon our strategy and thus the consequent tactics – something that we shall leave for a little while yet.

We have, loosely speaking, begun to evaluate decisions about the composition of the physical output – the so-called production mix.  Now, there is almost nothing, either positive or negative, that a good production manager can not ascribe, in one way or another, to the changes in the production mix.  The production manager can do this without fear of contradiction because, in fact, almost no one else understands the true impact of the production mix – often not even the production manager!

But we do understand – only too well.

We do, because we know how to strip out all of the raw material costs or 1:1 variable costs in the production mix leaving us with the bare essentials – we could call this the throughput mix (3, 4).  Moreover, we know that we must evaluate the throughput mix in relation to one thing and one thing only, the amount of resource consumed to produce the throughput mix on the constraint.

Let’s therefore look at this in a little more detail.  We need to better delineate some aspects that are particularly important in internally constrained environments.  Maybe we should describe these as generic tactics.  We need to do this in order to later appreciate some of the subtle changes that occur in the tactics once a system becomes externally constrained.

It becomes part of the exploitation strategy of internally constrained systems to maximize the throughput mix by including, as much as possible, products that generate high throughput per unit time on the constraint; these are the adults of our analogy.  In shorthand we might describe these as high “T/cu” products, where “T” means throughput and “cu” means constraint unit.  We saw this aspect demonstrated so well in the P & Q analysis.

However, I want to introduce the word “grade” to describe this aspect of throughput mix.  We want to substitute, wherever possible, higher grade unit throughput for lower grade unit throughput.  We want to produce “stars” not “dogs” if the market will allow us – and it should.  The overall grade is a reflection of the average throughput per unit.

Moreover, let’s call the current market capacity “market volume” and the profit “cash flow.”  Let’s have a look at the relationships.

Equally we could have used “capability” instead of “grade,” and “capacity” instead of “volume.”  In fact we should say capability before capacity, which is like saying grade before volume, which is no different from exploitation before elevation.  Indeed, in many industries, grade before volume is well understood – except that here we have no choice, we are internally constrained, we are at the limit of our volume, grade is (almost) the only thing that we can alter.

And I would like to embellish this further – or at least make it easier for me to understand – by adding some “gauges” to this; a sort of metaphorical dashboard for our system.  And let’s assume for the moment that this is the view prior to implementing our new-found knowledge.

We have a gauge for cashflow or profit (throughput – operating expense), reading “poor” at the moment; solvent but not swimming in cash.  We have a gauge for grade, it reads “low’ at the moment because prior to identifying the constraint standard cost accounting will have skewed the money making potential in this direction.  And we have a gauge for market volume – also reading “low” because without proper exploitation and subordination people won’t even understand the real potential of the system.  Let’s add one more gauge to our dashboard.  Let’s add a “constraintometer” to monitor the relative capacity of our constraint.  It’s reading 80%; heavily used, but capable of more yet with some careful exploitation and subordination.

Therefore, let’s exploit this internally constrained system and see what happens.

Volume through the constraint increases significantly and approaches its current limit.  The cashflow as a consequence becomes somewhat better – but nothing to write home about.  Note, however, that our grade or rather average grade remains low.  The only way to increase cash flow in this configuration is to increase the grade, or the average Throughput mix.  Let’s have a look at this.

Everything else stays constant,  but as our average grade goes up by the active substitution of higher grade throughput per unit output for lower grade throughput per unit output our cashflow becomes better.  Our volume remains on medium and our constraint is operating at its maximum.

This is a way of showing that in an internally constrained system it is the Throughput grade that is most important in raising the net profit of the system.  If you can actively substitute high grade products for low grade products in any new orders, then you will improve your cashflow.

Now a question; is this active substitution an example of exploitation or of subordination?

My answer to that is both!  We further exploited the constraint (and therefore the system as a whole) by subordinating our output decisions in order to maximise the throughput grade.  However, do we want to stay in this zone, the red zone of our constraintometer?  Shouldn’t we try to bring the operation down, or rather the capacity up, into the green zone?  In essence we are beginning to tread into an area where we need to distinguish between tactical and strategic decisions.

There is no need to tread, let’s rush headlong in!

 
Tactical And Strategic Decisions

In our evaluation decisions we are essentially asking what effect an actual action now, or a potential action in the future, has upon our profit and/or our return on investment.  These, after all, are our measures of success in a for-profit organization.  We need to know whether the change is a significant improvement or not, and if so, the magnitude of the improvement as well.

However, we can also examine these actions from another viewpoint – whether they are tactical or strategic in nature.  I will suggest that net profit is largely a tactical decision; how can we best maximize the return on our current assets.  Return on investment is largely a strategic decision; how can we best maximize the return on any additional assets.  It’s not a clear cut dichotomy, but it may be useful nevertheless.

We can place this distinction within the framework of our plan of attack, our 5 step focusing process.  Let’s show the generalized effect on throughput (T), inventory/investment (I) and operating expense (OE) within this framework.

Let’s consider the steps exploit and subordinate.  During the early stages of most implementations we don’t expect to make investment to increase output.  We expect our exploitation activities to cause output to rise.  Inventory, especially work-in-process may remain neutral or it may go down.  Operating expense may remain neutral or it may go down.  It may go down for instance if significant overtime was required in the past to meet due dates or to enable rework to be done (hidden or otherwise).  Because investment is most often not required at these stages let’s suggest that this is a tactical decision.

Let’s now consider the steps identify and elevate.  When we elevate a constraint we most often bring additional investment into the system, usually in the form of the purchase of additional capacity.  We may also need to increase operating expense in order to utilize the new capacity.  Thus inventory (investment) will increase and operating expense will most likely increase also, if only due to the increased depreciation of the new investment.  Because investment is most often required at these stages, let’s suggest that this is a strategic decision.

Both tactical and strategic decisions should have a positive impact of the productivity of the system.  This is easy to determine for non-investments.  But the moment we make an investment it is no longer straight forward.  Investments are apparently invisible to our definition of productivity;

The traditional approach is to allocate some of the investment via depreciation to operating expense thereby making the investment visible.  And traditionally this is done within the context of determining the tax payable on the throughput that is generated.  However, Caspari and Caspari have done a superb job of re-framing this aspect within the context of a POOGI bonus scheme.  Check the footnote at the bottom of this page for more information.  This is how we should treat investment if we want to improve and to grow.

Of course neither tactical nor strategic decisions should be passive – determined by the next accidental emergence of a new constraint.  They should be the result of active analysis of where we want the constraint to be.  After all, the location of the constraint dictates the way in which our firm will make money – and where our capital investment, product development, marketing and sales efforts will be.

Sometimes where there are significant cost/capacity differences across the system we may find that the constraint becomes by default;

(1)  the most capital intensive step in the process

(2)  the most capacity extensive step in the process

and this is the least likely to be overcome anytime soon because of;

(1)  direct cost in the case of the most capital intensive step

(2)  indirect costs of bringing up sufficient sprint capacity in the non-constraints for the most capacity extensive step.

The subdivision of whether something is tactical or strategic based upon external investment is a useful distinction; however, often substantial improvement can be obtained without additional investment at all.  In fact during this tactical phase questions of strategic importance will occur.  So, let’s not be mislead into believing that constraints are only broken by elevation.

Often, especially in the earliest stages of an implementation, proper exploitation may be all that is required to break an apparent constraint and to expose a new constraint somewhere else in the system.  Let’s call this an immature stage and let’s try and draw it.

So, once a constraint is identified, and exploited, that action alone may in a short period reveal another constraint in the system – before we have really made much improvement.  Our loop is very short; identify-exploit-identify.  Of course this is excellent.  We have jumped the system output up in the process and we can set out to exploit the next constraint and so on.  This is quite likely to happen when there is a lot of (historic) work-in-process and the effects of new policy changes have not yet had time to take full effect.

We can also break an apparent constraint simply by proper subordination.  Consider in manufacturing where non-constraints may be regrouping separately scheduled process batches together again – insubordination in fact (pun intended).  This will actually slow the whole process down and if it occurs in one area – maybe near the gating operation for instance then it may manifest itself as an apparent physical constraint somewhere else within the process.  The other extreme might be when sprint capacity is beginning to be eroded due to increased output, constraints will appear to be “breaking out” in various places – however the solution is to increase the buffer size.

Really the constraint in both cases is in the inertia of our subordination policies.  We can “short” the loop once again; identify-exploit-subordinate-identify.  Let’s add this.

Therefore we don’t have to go through the process in a linear fashion from start to end, reality is far more messy and interesting than that.  We can potentially break a constraint at any point in this sequence, and then we must go back to the first step and identify where the constraint has moved to (but usually it is fairly obvious).

In more mature implementations however the dynamic is a little more constrained.  In more mature implementations there is a strong interrelationship between exploitation of the constraint and subordination of the non-constraints.  Breaking a constraint is more likely to arise out of this interaction than either exploitation or subordination alone.  Let’s show this.

So we can break a constraint either at a tactical level within the exploitation and subordination phases, or at a strategic level by elevation.  In fact, in mature implementations buffer management will have warned us where the next constraint is most likely to be.  The occurrence of a new constraint should therefore not be passive and accidental; it should be active and pre-determined.  Clearly time to consider some strategic intent.

 
Static And Strategic

If the location of the constraint dictates the way in which our firm will make money, or the way in which our organization will make output, we may in fact have a preferred place for the constraint to be.  It may remain in the same place for long periods of time; both static and strategic.  Too often at first we are confused by our prior experience and the notion that bottlenecks “wander” or “pop up.”  We can control the process if we want to.  In fact we must.

Sometimes the methods of evaluating change are derided as short-term by those who do not understand their strategic significance.  Sometimes too, the focusing process, our plan of attack, is considered a short-term tactical methodology.  Both interpretations are shallow and impoverished.

There is a special richness in the focusing process that is lost on many people – after all it is not exactly explicit about it.  Others, however, have gone to considerable lengths to highlight this richness; often supplementing new words into the scheme.  The strategic nature of the focusing process is important.  If you are especially comfortable with this concept, or more so if you are especially uncomfortable with this concept, then at some time in the future please come back for an extended discussion here.

Ultimately, however, if we keep elevating our internal constraint – even if we choose to keep it in one selected place – then at some time we will move the constraint into the market.  Many argue that this is exactly where it should be.

 
Evaluating Change – External Constraints

Theory of Constraints had its genesis in internal capacity constrained systems.  A great deal of the early literature deals with this exclusively.  Sometimes then, there is a disjoint as we start to deal with external constraints.  I don’t believe that this disjoint exits in reality, I think that it is symptomatic of the history and some inertia in terminology as we move out from an internally constrained environment that is within our span of control towards an externally constrained environment that is often only within our sphere of influence – or so we like to think.

Because we won’t touch upon this again until the supply chain pages let’s be sure to understand that even though the constraints may now be external, the solutions are always internal.  Otherwise, how else could we ever bring about the solution?

Let’s return to our see-saw analogy once again, and continue from where we left off with an internally constrained system where one unit of operating expense can leverage 7 units of throughput.

Let’s elevate this system by extending the plank by 25%.  We know from earlier experience that we can expect 9 units of output.  But let’s see what happens this time.

Oops; we elevated the system again, yet this time something different happened!  We are missing 2 units of potential additional Throughput.  Yes, we still do have 6 units of profit there, but we would like two more units of profit except that the market has not supplied them; well not yet anyway – they are there somewhere but they won’t get on.  We are market constrained.  We are “externally” constrained.

How then do we evaluate change in this new circumstance?  Our constraint has now disappeared off into the market; the constraint has become nebulous rather than physical.

To answer this question we need to just slightly reframe the situation.  Sure, the constraint is now in the market, but ask yourself, where is the internal weakest link?  It’s still back in the physical process somewhere; most likely exactly where we last left it.  Let’s have a look.

The fulcrum is still in the same position and the balance point too is still in the same position and the secondary plank is still our weakest internal link.  We must continue to evaluate change in terms of the internal weakest link.

Back to our dashboard.  How has it changed since we last left it?

Well, clearly the cashflow and grade and market volume remain unchanged, but our “constraintometer,” our measure of our secondary plank has dropped way back down into the green zone.  Our internal solution to this “external” problem is to improve our marketing so that more people take advantage of the additional volume that we have to offer.

However, too often this is exactly where the disjoint occurs.  You see we have two pathways down which we can travel.

The first is to increase loading on the internal constraint.  Let’s have a look at this.

We do this by setting out our marketing to chase any added volume at the same average grade –the grade stays at medium as it has been for some time.  Well in fact we may even accept a “degrade.”  We accept without challenge the idea that  that any dollar will do so long as it exceeds all of the raw material costs or 1:1 variable cost content (5, 6).  We do anything to increase the throughput by accepting any additional volume of work that fulfils these criteria. 

What then of the other pathway?

The other pathway is the same as when we were internally constrained.  We accept grade before volume.  We actively seek through our marketing to substitute higher grade throughput for lower grade throughput – we have capacity, there are a number of clever things that we can do with it – things that are valuable to our clients and for which they are willing to pay (because they will make more throughput also).  Then and only then should we admit more volume (high grade throughput of course) and our cashflow will improve even further.

Let’s have a look.

Our cashflow goes even higher!

You know, we spend so much time and effort exploiting the financial advantage of an internally constrained system (because we have no choice) and then the moment that it becomes externally constrained we suddenly discontinue to properly exploit the financial advantage (because now we have a choice), and we so often decide to accept volume instead of grade because for maybe the very first time we can accept volume.

I’m afraid that this won’t do, not if we have a strategy.

We press the issue when we have an internal constraint that the sales people must be aligned with the value that the constraint can produce.  We don’t waste valuable and limited constraint capacity on goods of lower value when we can move goods of higher value, and by definition we can.  This is, after all, a central part of our exploitation tactic.  It shouldn’t be any different when the capacity has risen to such an extent that the constraint is now external to the system unless there are issues about solvency.

When we were internally constrained, the grade of the earnings were paramount because in fact we couldn’t affect the cashflow in any other meaningful way.  Does this change now?  Do we send our sales people out with instructions that any additional dollar is a good dollar just because additional volume is now an option?  Heck no!  We just trained them.  OK “trained salesman” is an oxymoron; rather, we just got them aligned with one set of ideals, then we throw that out and bring in another?  I don’t think so.

We are after both dimensions now, not just one or the other.  We want both the best grade of Throughput as determined the internal weakest link and the most volume of Throughput as determined by the capacity of the external marketing constraint.

To put it bluntly; we are after the “fat guys.”

How do we get them onto the see-saw?

We get them on the see-saw by changing our policies.  Our system will still contain some policy issues that stop our customers from buying our goods; moreover, our system will still contain some policy issues that stop our customers from paying more for the same goods.  This is because we fail to explain to our customers (and our salespeople) how our value delivers real additional value to them.  We have to surface and remove these policy issues.  If you like, we elevate the system by extending a policy plank, a policy extension, call it what you like; it most probably will cost us nothing but it will substantially improve the profitability of the organization.

 
We Can’t Evaluate Change Without A Strategy

It seems odd to say it, but we must; we can’t evaluate change without a strategy.  It seems odd because so often we infer that a strategy exists – our personal interpretation of what we deem the strategy to be.  However, we must make sure that we all know, understand, share, and are aligned with the same strategy – implicit or explicit.  We simply can’t evaluate a local tactic without knowing the overall strategic intent.  To develop this notion further, let’s return to our analogy one last time.

Remember when we had a mix of adults and children on the see-saw, each occupying an individual position?

We evaluated the change and found that our immediate throughput and therefore profit went up by $2½ per ride with respect to the starting condition, but that this was less than the $4 of additional throughput that was actually possibly.  But we had made an inherent assumption at that time that profit maximization was the strategy. 

What if the strategy had been to develop “thrills for mature adults?”  Then surely we might risk future success by having too many children on-board. 

What if the strategy had been to develop “a fun environment for children?”  Then having too many “old” people around might equally risk future success.

What if the strategy was “good value family fun?”  Then the current tactic might be perfectly acceptable.  And maybe, just maybe, we could have protected our throughput too.

Consider the following;

We made some assumption that “space” policies couldn’t be challenged!

But the more important point is we can’t evaluate a current tactic without knowing the strategy.  And therefore we can’t evaluate change without knowing the strategy.

Sure, we started with a context, our rules of engagement, but this is insufficient.  It is necessary to go one level deeper below the necessary conditions and the goal.  We need to know the next layer down, this is the first place where a "strategic intent" becomes apparent because it is the first place where non-generic company-specific objectives can occur.  Dettmer terms these first several layers below the goal “critical success factors” in his Constraints Management Model for Strategy (7).  We will cover this model in more detail in a page of its own.

In a for-profit organization, regardless of whether we are currently internally constrained or currently externally constrained, we must ask if we will we accept any sale that has a throughput that exceeds the raw material cost or the 1:1 variable cost?  This is not a trick question.  We think that we know the answer when we are internally constrained – at least in theory – because we know how to maximize the throughput on the constraint by adjusting the mix.  But even there we have to have an eye to the future and the overall strategy.

More importantly, because the answer is less clear, we need to know what happens in an “external” market constrained situation.  If for example our market is constrained; we can make several sales with a low grade Throughput now, and one sale with a high grade Throughput.  This isn’t a problem now, but it might be in the future.  It might be if our market thinks that we are a supplier of low grade Throughput goods or services.  We need to ask would we knowingly forgo a larger and on-going Throughput in the future in order to secure a smaller Throughput now?

Forget about discounted cash flow, just use common sense.

The answer is no!

Well, the answer is no, unless cash is the most important thing, which is to say that immediate solvency is such an issue that there might be no future unless we address the “now” both quickly and effectively.  But really this is an issue for solvency practitioners.

So, accepting a low grade Throughput now for most firms is trading short-term gains against long-term success.  It is a local optimization in time.  We trade a short-term, hopefully one-off, and local benefit for long-term, on-going, and global benefit.

Why, why, why, do we do this to ourselves?  We move away from local optimization in space in our process – and to be frank we are usually overwhelmed by the improvement – and then we completely fail to remove local optimization from time.

Why is this?  Any ideas?

Could it be impatient investors?  Unhelpful institutions?  Our cherished Christmas bonus?  Pressure from wage rounds?  The local council or municipalities’ new rate structure?  Hell no, the goal of our business isn’t to furnish cash to ever-increasing rate demands, is it?

Could these be excuses?  Excuses for the lack of something.  Excuses for the lack of an actual strategy.

Really, that is still too superficial; it is really the lack of understanding or belief in a strategy.  And we are not talking about a plan or an explicit document – we have all seen those.  We are talking about an implicit understanding between members of the group about where we are now and where we want to be in the future and how we are going to get there.

Once we understand the strategy, the tactics will fall into place.  Once we understand how we intend to exploit the system, the subordination issues will fall into place.  Moreover, once we have a strategy then having a unitary internal constraint makes a world of sense.  Where the constraint resides is no longer an issue.  We may modify our actions accordingly but the path is understood by all.

 
Subordinating The Tactics To The Strategy

Now, finally, we are in a position to explain and understand a conundrum that usually hooks people up and doesn’t let go – the dilemma arising out of subordination of the local to the global.

The dilemma is expressed at two levels, here is the first.

We must subordinate the current tactical constraint to the future strategic constraint.

Consider for example a tactical constraint that is the paint booth in a small engineering shop, and we want the constraint to eventually move to the assembly area of that shop.  In order to do so, we may have to forgo maximum financial throughput per unit time on the current tactical constraint in order to build the correct business for the future desired financial throughput on the chosen strategic constraint.

We can step this out, here is the second level.

We must subordinate the current strategic constraint to the future strategic constraint.

We can see exactly this in Toyota today as that company develops hybrid engine technology and brings it to market ahead of perceived demand (8).  The development of the Cummins Engine Company and the philosophy of the Irwin-Sweeny-Miller families is another exceptional example of this process (9).  Both of these firms leverage on the present to create the future.  The leveraging results in lower current profit than would otherwise be possible and a greater future (and total) profit than would otherwise be possible.  In fact, we could step back a little to contemplate how Toyoda Spinning and Weaving – a very successful firm in its own right, chose to, and evolved into an auto manufacturer.

Caspari and Caspari capture this dilemma which occurs whenever such a new strategic constraint is selected.  The dilemma is presented very nicely as a short-run versus long-run cloud (10).

Generically it looks like this;

No one would doubt that in order to have a process of on-going improvement we must have good tactics.  This, after all, is what good operations management – in fact any management – is all about.  We might call this the direction of the solution.  On the other hand, no one would doubt that in order to have a process of on-going improvement we must also have good strategy.  This, after all, is what good leadership is all about.  We might call this the direction of the company.

A conflict arises, however, from the extension of these needs.  In order to have good tactics we must exploit the current constraint.  But, also in order to have good strategy we must move the system towards the future desired strategic constraint – otherwise our leadership decisions will not be implemented.  And herein lies the dilemma; we can not both exploit the current constraint and not exploit the current constraint (move the system towards the strategic constraint).

How can we break this dilemma?  Let’s see.

We can break this dilemma if we are willing to subordinate the short-run to the long-run in order to undertake a process of on-going improvement.

In fact, if we substitute “long-run” for “good strategy” and “short-run” for “good tactics,” then we can clearly see the relationships.

And again the solution is the same.

Then I think that we can see a generic cloud that covers many more systems and personal situations than just this one.

We must not locally optimize in time – unless we are willing to sub-optimize globally over a longer period.  Moreover, our short-term results only have significance with respect to our overall strategy.  If there is no strategy then short-term gains will be overwhelmingly attractive.  If there is a strategy and the strategy is understood by all, then the future gains will be far more attractive.

Subordination remains the key; we must subordinate the non-constraints to the constraint of the system and we must subordinate the tactics to the strategy of the system.  This requires good leadership.

 
Levers Of Control – Levers Of Success

Robert Simons in Levers of Control wrote about the need to establish a critical bridge between the disciplines of strategy, accounting, and control (11).  He did so using 4 systems as his levers.  We can extend his analogy from levers of control to levers of profit in for-profit organizations, and levers of success in for-cause organizations.

The terms “levers of profit” and “levers of success” highlight that we leverage the system via a constraint in the physical system.  We can leverage the system by changes in investment and expenditure, but more importantly we can also leverage the system by changes in policy.  In the end it is really people who offer the real leverage in these man-made systems.  Regardless of how we leverage the system we must not forget that the fulcrum “under” the lever is time.

 
Summary

We ended the preceding section on the note that if there is one department that can block all others then that department is finance.  We have seen, however, that there is no need for this to occur.  Indeed financial accountants – the very people who deal with and understand flows of money – will wonder what all the fuss is about.  After all it’s just common sense.

We can make a quick and stunningly effective evaluation of changes that are improvements by taking care to use the 3 fundamental measurements of throughput, inventory/investment, and operating expense while remaining mindful of where the pivot point and the constraint are now and indeed where we would like them to be in the future.

Let’s turn our attention now to some of the broader aspects, aspects that make all of this happen; aspects of leadership.

 
Footnote

This page supersedes one initially entitled “accounting for change,” which is included here as a link as it is still referenced by a number of other pages.  Rather than use this link, there are two excellent sources for accounting professionals.  They are;

Caspari, J. A., and Caspari, P., (2004) Management Dynamics: merging constraints accounting to drive improvement.  John Wiley & Sons Inc., 327 pp.

Corbett, T., (1998) Throughput Accounting: TOC’s management accounting system.  North River Press, 174 pp.

 
Postscript

I originally wrote this page because I wanted to address evaluating change without recourse to equations – well at least not straight away.  This was the rationale for the see-saw analogy.  But there was another motive.  I was “irked” that the texts said that once we move from internally constrained to externally constrained “any additional cash will do.”  I was concerned that if you are going to invest cash on a project then your really want the best grade return that you can obtain – even if you have to wait a while.

Moreover, when I wrote the original version of this page Viable Vision was little known and even less understood.  Yet the heart of Viable Vision is exactly the high grade exploitation of the external market.  I’m sure that as the text books arrive at new editions this necessary condition of maximising throughput in externally constrained systems will be much better explained.

Of course Viable Vision aims at turning the top line (annual sales) into the bottom line (net profit) in 4 years.  This seems unbelievable, but it is all a matter of strategy.  If we have mediocre expectations and mediocre strategy, then we will get mediocre results.  If we have a strategy that is staged around the breaking of a sequence of internal and external constraints while all the time seeking high grade throughput then Viable Vision in various environments is an absolute reality.

 
References

(1) Goldratt, E. M., (1990) The haystack syndrome: sifting information out of the data ocean.  North River Press, pg 98.

(2) Goldratt, E. M., (1990) The haystack syndrome: sifting information out of the data ocean.  North River Press, pp 96-97.

(3) Caspari, J. A., and Caspari, P., (2004) Management Dynamics: merging constraints accounting to drive improvement.  John Wiley & Sons Inc., pp 115, 118-119.

(4) Corbett, T., (1998) Throughput Accounting: TOC’s management accounting system.  North River Press, pg 55.

(5) Schragenheim, E., and Dettmer, H. W., (2000) Manufacturing at warp speed: optimizing supply chain financial performance.  The St. Lucie Press, pg 240.

(6) Caspari, J. A., and Caspari, P., (2004) Management Dynamics: merging constraints accounting to drive improvement.  John Wiley & Sons Inc., 327 pp.

(7) Dettmer, H. W., (2003) Strategic navigation: a systems approach to business strategy.  ASQ Quality Press, 302 pp.

(8) Liker, J. K., (2004) The Toyota Way: 14 management principles from the world’s greatest manufacturer.  McGraw-Hill, pp 71-84.

(9) Cruikshank, J. L., and Sicilia, D. B., (1997) The engine that could: 75 years of values-driven change at Cummins Engine Company.  Harvard Business School Press, 587 pp.

(10) Caspari, J. A., and Caspari, P., (2004) Management Dynamics: merging constraints accounting to drive improvement.  John Wiley & Sons Inc., pp 261-262.

(11) Simons, R., (1995) Levers of control: how managers use innovative control systems to drive strategic renewal.  Harvard Business School Press, 215 pp.

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