Part 2: Implementing TLS (Theory of Constraints, Lean, and Six Sigma)

I am flying back from teaching a Green Belt course in Las Angeles, California and as promised, I will continue my “journal” of TLS implementation efforts at an industrial organization.


In the last blog, we discussed how this organization was using the metric of “Yield” to score their production process success. We discussed that this metric only shows you what happens at the end of their process, and doesn’t give visibility to the success of the many internal steps. In order to implement TLS, we needed to have a better way to look at our process systemically. We also needed to have a way of determining where our constraints are. Following the “Lean” methodology, we decided to use O.E.E.(Overall Equipment Effectiveness) as a primary facility metric. We had an overall “Plant” OEE, and we had OEE’s per line and per product. OEE would give us visibility to how we were performing with respect to Performance (Ratio of Daily production to effective capacity), Quality (the number of Good vs. Bad product), and Availability (ratio of used production time to available production time). We also needed to take data on each of the critical steps in each line to understand where our constraints or bottlenecks were. We defined six critical points that were common to each line (because the lines were almost replicates of each other).

Our plan at the moment is to define each critical point in the lines in a metric and describe throughput (with a common denominator) of each point. We will track the throughput on a continual basis. This will tell us our constraint, and we will set our process TAKT time to the constraint. We know what our goal TAKT time is … but we cannot set our process TAKT time to produce more than our constraint. Therefore, if our process TAKT time does not meet our goal TAKT time, then we use Lean and Six Sigma tools to cross the chasm. In my next blog, I will talk more about our Implementation progression and about the synergy between the three methodologies that make up TLS (Theory of Constraints, Lean and Six Sigma). I will also give more information on TAKT time to those who have not heard of the concept.

“Until the next thought”