Performance Problems Are Hidden in Our Assumptions

Some performance problems are hidden in our assumptions.

In a project we carried out with one of the world’s largest cable manufacturers:

The initial setup time we recorded was 2,300 minutes.

And that duration had been accepted as “normal” for more than thirty years.

⚠️ The equipment was suitable.
⚠️ The operators were experienced.
⚠️ The constraint was the design of the workflow rather than the technology.

Following direct observation and SMED work, the measured setup time fell to approximately 900 minutes. Using the same measurement scope, this represents a reduction of about 1,400 minutes per setup, or 61%.

What does this mean?

The annual capacity equivalent of this reduction depends on how many setups occur each year, how long the machine actually stops and the net daily operating time. Person-minutes of total team effort must not be confused with minutes of machine downtime.

A shorter setup can release capacity. Turning that capacity into increased production also requires sufficient demand, material availability and suitable conditions at the other constraints in the flow. Whether the bottleneck has been eliminated must be verified separately using flow data.

The key lesson:
Organisations are often slowed by unquestioned assumptions rather than mistakes.

So is asking “Why was this not done all those years?” useful?
Often, no.

It is difficult to attribute the past to a single cause. A lack of knowledge, priority, time or resources may also play a part. In this case, our productive starting point was to question the familiar method together.

A fundamental premise of lean thinking is:
We do not blame the current state.
The current state is the starting point we need to improve.

We celebrate success and move on. The main focus is always a better future state.

There is no perspective vaccine to change our point of view.

The closest thing to it is:

The philosophy of lean thinking.