• Published by: Anna Robson

The Theory of Constraints

Any manageable system is limited by at least one constraint. What if this system is the most complex manufacturing process in existence? Providing optimized production scheduling for wafer fabs, we deal with a great number of constraints.


In the early 80s, Eli Goldratt, a physicist turned management guru published his book "The Goal". Why is it important? In the book, he underlined the foundations for what was described later as the "Theory of Constraints".

Although it was written nearly 40 years ago, and manufacturing industries have since evolved, many of the principles stated in the book remain relevant today. They also mirror what we do at Flexciton, helping wafer fabs to improve performance by optimizing the way the fabrication process is scheduled.

Let us give you a snippet of what is it about by sharing the three key messages of the Theory of Constraints:

  • "Throughput is the money coming in." Balancing the flow of product through the plant with demand from the market is critical for the business performance. Throughput is usually a priority KPI we follow to calibrate our scheduling solution for a given fab.

  • "Every hour lost at a bottleneck is an hour lost in the entire system." Based on the Wafer Fab Performance Analysis which we have carried out for various fabs, we see that a small number of tools are bottlenecks, yet this seemingly little number are responsible for substantial wait time in the fab.

  • "We shouldn't be looking at each local area and trying to trim it. We should be trying to optimize the whole system. A system of local optimums is not an optimum system at all." At Flexciton, we first take a global look across the whole fab, then we identify areas where optimization would bring the most significant improvement for the entire facility.

The very first step for improving the fab productivity and KPIs such as throughput or cycle time is to identify the system's constraints and where the efficiency is lost. Flexction's Wafer Fab Performance Analysis takes a global view of a fab and pinpoints the areas or specific toolsets responsible for lower productivity. This analysis often brings unexpected and eye-opening results.

We are currently running the Wafer Fab Performance Analysis fully remotely and free of charge. If you wish to discover more, please click here to get in touch with one of our consultants.