Value stream analysis is an effective way to identify improvement opportunities within a product or service family's value stream, envision a leaner future state, and develop an actionable value stream improvement plan to achieve the future state. It's bread-and-butter stuff for the lean practitioner.

Most folks are well-acquainted with the value stream map's lead time ladder, and many people are familiar with the concept of rolled throughput yield. However, based on my humble observation of hundreds of value stream maps, there are precious few who incorporate a rolled throughput yield (RTY) line within their maps.

It's a shame.

The process yield data typically are already captured in each process's data box. From there, it doesn't take too much effort to build out the RTY line.

Know that yield represents the percentage of the process output(s)—e.g., fabricated part, assembly, analysis, transaction—that do not require any sort of rework or replacement, at any time. In the service and healthcare industries, this includes completeness and accuracy, the first time.

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