July 1, 2005
By Darren Dolcemascolo
I have visited several factories that have successfully implemented one-piece flow. On the other hand, I have also visited unsuccessful factories that have attempted to implement one-piece flow but have not been able to achieve it. Two months ago, I wrote an article that covered one missing element in many of the unsuccessful attempts, standardized work. Another key element to achieving one-piece flow is achieving basic stability. In fact, this is a prerequisite to achieving true one-piece flow.
What is basic stability? If you are familiar with EMS Consulting Group, you know that we have taught and continue to teach that to achieve one-piece flow, one must have:
Highly capable processes. Processes must be able to consistently produce good product. If there are many quality issues, one-piece flow is impossible.
Highly repeatable processes. Process times must be repeatable as well. If there is much variation, one-piece flow is impossible.
Equipment with very high (near 100%) uptime. Equipment must always be available to run. If equipment within a manufacturing cell is plagued with downtime, one-piece flow will be impossible.
The above three elements are critical to one-piece flow success; together, those three elements define the term "basic stability." If basic stability is in place, one-piece flow is possible (and not very difficult to achieve).
There are several tools that can help an organization achieve basic stability. Let's review three of them briefly.
1. Total Productive Maintenance (TPM). The goal of TPM is to improve Overall Equipment Effectiveness (OEE) by eliminating the "Big Six Losses"
Setup and Adjustment Losses
Idling and Minor stoppage losses
Quality defects and rework
Start-up/yield losses (reduced yield between machine start-up and stable production)
2. 5S. The five S's are Sort, Set-in-Order, Shine, Standardize, and Sustain. Together, the five S's work to organize and maintain an organized workplace. A workplace that has implemented 5S is one that has predictable, repeatable processes.
3. Quality Tools / Six Sigma / Statistical Methods. Very often, the quality tools. now most closely associated with six sigma, must be applied to reduce variation in a process.
Basic stability is critical to achieving one-piece flow in a manufacturing cell. Using 5S, TPM, and statistical methods, one can reduce variation and create the necessary conditions for one-piece flow.
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