ABSTRACT
Process variation is the bane of one-piece flow. There are times when processes simply are not capable, because of the variation in the process or in the design of the product, of achieving one-piece flow in the short term. It stands to reason that process variation must be understood with solid root cause analysis and then, like a weed, pulled up from the roots. By product variation we are not talking about options to the product but variation within the process itself. The most effective tools we have at the early stages of combating process variation are
1. Standard Work 2. Workplace Organization (5S) 3. Setup Reduction (SMED) 4. Total Productive Maintenance
Most times a layout based on the process flow of machines and assembly can be accomplished concurrently with these tools. It is left up to the business owner, operations manager, manufacturing engineer, etc. engaged in the continuous improvement to determine if the time, risk tolerance, leadership support, capital, and knowledge are all present in the culture to implement one-piece flow all at once. The downside to erring on the cautious side-of not going for the touchdown (one-piece flow) in one play-is the economic opportunity cost. However, as we all know, there will be tangible financial and customer service-level benefits to implementing the four tools above, even if we don’t go for the whole enchilada at once.
