Value stream mapping is a lean-management method for analyzing the current state and designing a future state for the series of events that take a product or service from its beginning through to the customer.
Contents:
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Value Adding (VA): any activity that your external customers value, and would be willing to pay for.
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Necessary Non-Value Adding (N NVA): any activity that is necessary but does not add value, for example any necessary support processes, legal regulatory requirements, etc.
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Unnessary Non-Value Adding (U NVA): any activity that is unnecesssary, a.k.a. waste.
In order of importance.
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Value Time (VT)
- The time spent on adding value. This is actually performing the work.
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Process Time (PT)
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A.k.a. touch time, work time, cycle time.
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The time it takes to actually perform the work, if a person is able to work on it fully and focus on it fully.
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Include task-specific doing, talking, thinking, etc.
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Lead Time (LT)
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A.k.a. throughput time, turnaround time, elapsed time.
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The elapsed time from when the input to a step is available, until the step is compeleted i.e. the work is sent along to the next step.
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Include Process Time, not just the waiting time.
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Percentage Activity (%A)
- Calculate (PT / LT) * 100
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Input Percentage Complete & Accurate (%C&A)
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The percentage of inputs that are fully usable, i.e. that are complete and that are accurate, as measured by the person receiving the inputs.
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Similar to "first pass yield" in manufacturing.
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Rolled first pass yield (RFPY)
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A.k.a. %Clean, %C&A for stream
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Calculate %C&A * %C&A * %C&A ...
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The percent of value stream output that goes through the process cleanly, i.e. without any need for rework.
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Number of Handoffs (#HO)
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Number of IT Systems (#IT)
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Freed capacity
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Overproduction
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Inventory
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Waiting
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Over-processing
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Errors
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Motion (people)
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Transportation (material, data, etc.)
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Underutilized people