The five steps of focusing are in the Core of TOC.
When applying them to a production environment that has a permanent and expensive bottleneck step 2 is extremely challenging. The decision of how to exploit the system’s constraint(s) demands a sophisticated production plan.
In 1975 Eli Goldratt and his partners built a software called OPT. It was based on simulation software called SPSS. It provided the platform for Finite Forward Scheduling system.
OPT laid the foundation for TOC.
TOC was developed because the software worked and brought significant results! OPT contributed the concepts of Flow and Focus to the core of TOC. Inherently in the OPT there were the concepts of managing flow (one of the 4 points of Standing on the shoulders of giants) and the build of outstanding plan for carrying out the decision of how to exploit the constraint (step 2 of the five steps of focusing).
The OPT was for MTO.
Nearly 40 years later – Emanuele Strada has done the same for MTA.
By using advanced software, he has built dynamic modeling to demonstrate and simulate the behavior of the production environment under the MTA regime. It is a unique work. The modeled plan was successfully incorporated into the operation of a mega production facility.
This work coincides with Step 2 of the five steps of focusing: Decide how to exploit the system’s constraint(s). The five steps of focusing are a part of the Core TOC. Yet, they provide the framework and the guidelines of WHAT should be done. It is down to the practitioners and the implementers to find the HOW.
The “Decide” means in this environment building a production plan.
The MTA modeling takes into account several factors that complicate any attempt to build a production plan, such as: process steps dependency, process performance variation, material scheduling, process capacity and capability, batch size logic, order due date commitment, demand volume and product mix variation, resources availability, skills, process routes while considering local versus global optima.
In order to properly manage the flow, there is a need to consider all of the above factors, together with another very important element in the equation – time!
Both OPT and the MTA modeling build the production plan through simulating flow with time progression.
The dynamic process modelling provides the ability to learn and assess how the above factors interact among themselves. It enables to analyze and review the assumptions behind the suggested solutions. It reduces the risk of implementation failure and predicts and boosts the effectiveness of the proposed solution in a specific environment.