Simply Lean By Dave Turbide

Written by Dave Turbide

A commentary elsewhere on this site – Simplified Lean – A Recurring Theme at APICS 2004 Fall Conference, 11/4/2004 – outlines a presentation I gave at a breakfast session at the named event regarding Simplified Market Pull (SMP), an approach to Lean manufacturing that delivers quick results without a costly and traumatic conversion to flow manufacturing. Purists will complain that anything short of pure flow isn't "Lean" but I believe that any technique or approach that delivers shorter lead-time, reduced handling, more flexibility, etc. qualifies and if it can be done more quickly and affordably, so much the better.

The referenced article nicely summarizes the primary characteristics of SMP. First off, it is an approach that only works in companies with excess capacity; unfortunately that includes a lot of companies these days. SMP is a control system that manages the release and flow of work in a plant with a minimal amount of WIP backlog, so a major part of the implementation process is flushing excess WIP out of the plant. In describing SMP, one tends to focus on that process (reducing WIP) since it is the most visible part of the implementation and the most difficult thing to get your arms around.

We have been taught to value a good, solid backlog. Production workers find comfort in the piles of work that await their attention. Management views a full plant as one with plenty of business and revenue. A full plant is a happy plant. But a full plant is also one with long lead-times, contention for resources, and considerable waste. The interesting thing is that many plants operating below capacity are also jammed with WIP and struggle to meet due dates. SMP is designed to address this problem.

Back to flushing WIP out of the plant. You will recall the classic APICS 'sink' diagram that illustrates the relationship between WIP and lead-time. With a full sink, the average job must work its way through the other jobs that are already in the shop until it finally makes its way through to completion. If the level of WIP is reduced (water drained out of the sink) jobs move through the process faster.

There are two ways to lower the water (WIP) level: open the drain (increase output) or close down the tap (reduce the input). The latter alternative is far easier to accomplish than the former, although it is difficult mentally and emotionally. It just seems unnatural and risky to hold back work – not release it to the shop – and it's hard to see how that can actually help get it done faster. The SMP implementation process is a proven method for managing that transition. Work is held until the 'proper' time for its release, then input is carefully managed to maintain the lower WIP levels. A priority management system insures that work is completed on time, in a lot less time than was previously required.

And that's SMP in a nutshell. WIP reduction is not rocket science, obviously, but it does take discipline, and an understanding of how you're going to keep work moving appropriately and get jobs completed on time in a 'lean' low-WIP environment. The tremendous benefits of a lean plant do not come free, but they don't have to be expensive and difficult to achieve. There are alternatives that should be explored to find the approach that best fits your needs, situation, and capabilities.

For more than twenty-five years, Dave Turbide has been a consultant specializing in manufacturing technologies, consulting, and education. He has extensive first-hand knowledge of manufacturing functions and management practices, automated information systems, and vendor manufacturing software offerings. He also has experience in industry analysis, writing, engineering, project management, technical analysis, and management. He has exceptional analytical and communication skills as demonstrated by his published books, articles, papers, and speeches.