Value stream mapping glossary

The thirteen figures this product calculates, each with the formula it uses and the passage of the methodology that argues for it. Every definition here is the one shown inside the tool.

• Takt time

  The rhythm the customer buys at: available working time divided by demand. Not a measure of how fast the line runs — a target it should match.

• Lead time

  How long one piece takes to travel the whole stream, waiting included. Measured along the critical path, so parallel branches do not add up.

• Processing time

  The time a piece is actually being worked on. Everything else in lead time is waiting.

• Process cycle efficiency

  Value-added time as a share of lead time. Single-digit percentages are normal, which is the point of drawing the map.

• FPY

  The share of pieces a process gets right the first time, counted rather than assumed. Rework that was recovered still failed first pass.

• Rolled throughput yield

  The chance a piece passes every process first time, all of them multiplied together. Falls faster than any single yield suggests.

• OEE

  Availability times performance times quality. All three, or the product calls it an A×Q score instead and says which component is missing.

• Total inventory

  Everything sitting between the processes, counted in pieces, and the biggest component of lead time on most maps.

• Required operators

  Manual work content divided by takt. What the flow needs, not what is rostered. The range beside it is the same figure in whole people: the theoretical minimum if work can be shared across processes, and the count if every process keeps its own operator.

• Balance efficiency

  The work the stream needs, in operator-equivalents, over the operators actually assigned to it. Deliberately uncapped: above 100% means the work exceeds the people, which is a gap and not a triumph. This is a staffing ratio, not the line balance efficiency of textbooks.

• EPEI

  Every Part Every Interval: how often a process can come back round to the same part. A capability derived from changeover time, not a target typed in.

• Pitch

  Takt multiplied by the pack quantity — the interval a levelling box releases work in.

• Measurement coverage

  The share of inputs that were measured rather than estimated. Findings drawn from estimates are reported with lower confidence.

This definition is the one the product itself shows, read from its interface catalogue at build time.

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