Continuous Improvement: Prevent frustrations related to the S curve

When implementing some solutions, like in continuous improvement, project managers better take care about the frustrations related to the S curve.

S curve

S curve

The “S curve” is the shape of the performance curve over time. It describes a latency (t1) before the performance p1 takes off after the improvements have been implemented, then a more or less steep rise before stabilization at the new level of performance p2.

This latency time after the first improvements until improvements become noticeable has several possible causes and can pose different problems.

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The most trivial reason for a lack of significant effects after a while is that the solutions put in place do not produce the expected effects. It is therefore advised to estimate in advance, at the moment improvements are implemented, when the effects should be noticeable, in order to have an alert when the estimated time is elapsed.

Another trivial reason is a long cycle time. This may be the case with lengthy process of transformation, processing time or latency inherent to the process before the success of the operation can be judged. Typically, these are technical lead times, time required for chemical or biological transformation processes or “responsiveness” from third-party organizations, etc.

The delay may be due to the improvement process itself, which may require several steps such as initial training, implementation of the first improvements, measurement of their effects and time to analyze them.

Another reason, that may be coupled with the previous one, is Little’s law. It states that the lead time through an inventory or queue of work in progress (WIP) is equal to the value of this inventory divided by the average consumption. This means that if the improvement occurs at a point decoupled from the measurement point of its effectiveness by either inventory or WIP, the effect must first propagate through the queue before it can be detected. Everything else being kept equal.

Please note that this delayed improvement phenomenon or “S curve” described here in the context of continuous improvement can be found in the implementation of any project.

This discrepancy can be a problem for Top Management awaiting return on investment and wishing it as quick as possible. This is all the more true if the activity is highly competitive because an improvement can determine the competitiveness and/or profitability of a project, an offer or even of the whole organization.

It is therefore recommended that the project leader reminds the likeness or certainty of the S curve, even to the managers pretending to know it. Under pressure of business they tend to “forget” it.

The second problem with delayed effects concerns those closer to execution who expect some benefits from improvement, such as problem solving, elimination of irritants, better ergonomics, etc.

Assuming that the operational, shopfloor staff have been associated with the improvement, their frustration and their impatience to see changes is even more important. Without promptly demonstrating that “it works”, there is a significant risk of losing their fate, attention and motivation.

In order to prevent this, the project manager must choose intermediate objectives in short intervals in order to be able to communicate frequently on small successes.

The recommendation  is to look for a weekly interval and not exceed the month. The week represents a familiar time frame to operational staff, and the month being, in my opinion, the maximum limit. Beyond the month it usually becomes an abstraction and attention gets lost.

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Stuck with continuous improvement?

This post is a kind of post scriptum to “Improving  50% is easy, improving 5% is difficult” in which I described 3 stages of improvement and ended stuck with continuous improvement as the Return On Investment (ROI) in C stage was not worth going on.

Continuous Improvement

Now assume it is not possible to radically change the process (kaikaku), because for instance it has been approved by some authority (customer, regulatory…), being on the verge of C stage does not necessarily mean this is permanent.

If the limitation to improve further are skills or experience, the situation may change over time as trainings are delivered, experience is accumulated or necessary skills hired.

If the limitation is the cost of some solution, like changing material or buying some equipment, this too may change over time and become affordable / change the ROI, thus providing opportunities to improve further without changing everything.

What wasn’t possible or reasonable at some point may become possible and meaningful.

It is therefore important to revisit the assumptions and conclusions of the improvement workshops /projects periodically and check if some conditions have changed in a favorable manner.

This is also why, after a Value Stream Mapping and/or some diagnostic was done, designing the future state should first attempt to design a perfect process. This frees the designers from actual constraints and limitations and can lead to interesting solutions.

In a second step, the constraints and limitations are brought back in and the ideal solution trimmed down to what is possible given the limitations, e.g. state of industry vs. state of art, technological or economical limitations, limited know-how, etc.

But all brainstorming ideas and drafts of a perfect process/ideal state should be kept in a kind of think tank and periodically checked. It may happen that one of the ideas, impossible at a given moment can now be envisioned, thanks to some evolution.

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What is Kaikaku?

Kaikaku is one of these Japanese words which found their way into the Lean lingo. Kaikaku is usually translated into “radical change” or breakthrough.

my tiny Japanese dictionary proposes “reform”, “renovation” and “reorganization”.

“Doing” kaikaku means introducing a major change in a process in order to drastically improve it (quantum leap). Kaikaku is therefore “opposed” to Kaizen, which is incremental, small steps, improvement.

Kaizen is often praised for being a safe and low-cost improvement way. By changing only one thing at a time and trying allows to observe the effect of the change and to learn from this experience.

Kaikaku will discard much if not all from the existing solution and introduce big change(s). The usual set of parameters and previous accumulated learning may not be useful anymore. The new process is likely to be unstable until all new influencing parameters are fully understood and under control. Therefore Kaikaku is feared as risky.

Yet Kaikaku is not all bad. Once Kaizen has given all that can be reasonably achieved (timely and in terms of Return Of Investment), a radical change may be the only option to improve further.

Kaikaku is often understood as innovation, bringing in some high-tech or top-notch technology.

Indeed, if a manufacturer changes his production way from cutting away material to additive manufacturing (3D printing to make it simple), it is a disruption and potentially a quantum leap in productivity, efficiency, lead time, customizing, etc.

Kaikaku can be more mundane than that, like reorganising the way of operating for instance.

I remember working for Yamaha music, assembling home cinema receivers and CD players, when we heard the headquarter was planning a switch from long linear conveyor belt assembly lines into small autonomous cells, it was kaikaku because it was disrupting decades of streamlined production.


Chris Hohmann in Yamaha’s headquarter, Hamamatsu city

Many Kaizen events (also called kaizen blitz) are in fact small kaikakus where drastic changes are made in short time. Those events are not the best way for try-and-learn, it’s more often one expert moderating a workgroup and leading it to a disruptive solution, hence kaikaku.

If you’d like to share your thoughts or experience, use the comments below.

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Improving  50% is easy, improving 5% is difficult

It is with this enigmatic sentence that one of my Japanese mentors introduced the growing difficulty with continuous improvement.

What it means is that at the beginning of an improvement program or when starting in a new area, the first and usually the easiest actions bring big improvement, hence the “easy” 50%.

This is also known as “reaping the low hanging fruits“, another metaphor for earning easy results with very reasonable effort.

Once these easy and quick wins are done, what is left to improve requires more effort, more time or more investment.

The improvement curve is therefore asymptotic and it is increasingly difficult and expensive to squeeze out the last improvement potential, hence the “difficulty to improve (the last) 5%”

The graph shows the 3 stages of improvement

Continuous ImprovementA: quick and easy, few actions, visible results, big leverage, usually a leap in performance. Excellent Return On Investment (ROI).

B: second stage in continuous improvement, more effort and investment is necessary, but the ROI is still worth it

C: “chasing the decimals” : huge efforts and investment are required to squeeze out the last potential. The ROI is not worth it.

At some point, the Return On Investment (ROI) is not worth going on. This means that improving further what exists and/or the way it has been done until now is no more meaningful. What is required is a breakthrough, a radical change.

This is where kaizen (continuous incremental improvement) must give way to kaikaku (radical change), or in other words: as the old process or usual way cannot be further reasonably improved, it must be totally reconsidered.

Yet in many cases this is the upper limit of improvement as the process cannot be changed. Too often redesigning the product or process is not possible:

  • Design has to be approved or the new product/process has to undergo lengthy and costly qualification (pharma, automotive, aerospace…)
  • Remaining life is not long enough to pay for
  • Facilities are not flexible, can’t be modified
  • The modification would break some contract

The continuous improvement is often limited by options and decision made in early design and development stages, a fact I discuss in >this post<

Related: Stuck with continuous improvement?

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Continuous improvement: how easily focus is lost

In an industrial environment improvement opportunities are literally infinite, especially if nothing has been done so far about improvement and maturity, about industrial best practices and considering methodologies like Lean, Theory of Constraints (ToC) or Six Sigma was nearly nonexistent.

When starting to improve, it happens quite often: committed people get lost and lose focus. Instead of concentrating on the core issue to achieving the Goal,  they dilute efforts on lesser important subjects, secondary objectives or even unimportant things.

As a consequence real improvements are delayed or even won’t happen.

How to prevent this from happening? Here are three things that will help:

  • Choose proper KPIs
  • Have a sponsor keeping some distance
  • Start with a Goal Tree

Choose proper KPIs

Measurement is the first improvement step. Choose the (few) KPI(s) that really reflect the achievement of the assigned key objectives and assess the effects of improvement efforts with these figures.

Assigned key objectives points to a Goal set by the organization’s owner or the delegate executives. Bottom-up chosen improvement targets lead most often to local optimization which is scarcely contributing to the overall system improvement, hence the reservation about point kaizen or kaizen blitz workshops focused on local improvements/problem solving.

Expected improvement is generally about productivity, quality, timely deliveries or any combination of them. Outcome should be measured in physical units, e. g. widgets per hour, right first time rate or on time in full (OTIF) deliveries.

Pitfall to avoid with KPIs is to choose activity-related instead of outcome-related ones, like the number of kaizen events held in the week rather than additional widgets made ready for shipping.

Teams may get some scolding for not delivering the expected results even though they were convinced to have worked hard and gotten nice results. They are just not aligned with top management’s expectations.

Back-standing sponsor

Having someone higher ranking / legit, keeping some distance from details and looking at the project with a broader perspective is a good way to prevent shop floor teams to get pulled down into details and away from their objective.

The sponsor should have authority to both help the team to overcome some difficulties, when decisions are to be made with other stakeholders and authority to demand regular reports and direct the team when necessary.

Regular reports and expectation of results are powerful incentives for the team not to lose themselves during their improvement journey.

Having a back-standing manager is common practice in the consulting business where a manager will follow, support and coach the consultants shop floor team, making sure focus is kept on the right objective and progress is consistent.
Some customers can’t understand the importance of this management they consider costs added, not value-added, an easy way to charge more (Yes this may happen, but let’s assume the consultants we’re considering are good ones with real care about delivering value and some ethics).

Well, the cost of meaningless efforts, wasted time and resources on ill-chosen or defined objectives is often much higher than the cost of the back-standing manager.

When the Goal is defined at the top-level and the objectives assigned to the teams, the project governance is usually defined as well, with someone high-ranking taking the sponsor / jury role. Bottom-up initiatives do not always have it.

Start with a Goal Tree

My regular followers are used to read my posts promoting this fantastic tool: the Goal Tree. Many of you readers may not yet be familiar with Goal Trees, and I strongly recommend you to learn more about them and evaluate the potential benefits using them.

At the beginning of a project, building a Goal Tree is a smart investment worth the couple of hours required: a well-built Goal Tree will give guidance toward the assigned or chosen Goal as well as the associated few Critical Success Factors to achieve and the list of Necessary Conditions to fulfill.

The Goal Tree is built upon necessity logic (in order to achieve… we must…) and thus prevents to get lost in nice-to-haves or irrelevant “improvements”.

From the moment I used a Goal Tree from the start myself, I kept focused, consistent and more efficient for myself or the teams I worked with. Conversely, when I thought I could save the effort starting with a Goal Tree it went not that brilliantly, with some deviations, drifting and the like.

These unpleasant experiences were powerful reminders, especially when the back-standing manager legitimately “kicked the a**”.


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