Value Stream Mapping
In a value stream we identify all the added-value and non-added value activities. This is needed to complete a value stream map.
The value stream will consider the production flow from the customer requirements (where applicable internal ones) through to the suppliers (raw material and purchased part delivery).
The value stream perspective provides an overall picture that must be taken into account beyond a singular manufacturing process.
The overall picture should highlight improvements throughout the entire manufacturing process and not only in the discrete processes.
The observation of the entire value stream from raw material to the end customer is too complex to start with and must be broken down into individual smaller “streams”.
As an illustration, two popular terms are used to define the value stream landscape or VSM = Value Stream Mapping (or also named Material and Information Flow Analysis (MIFA)
Within the landscape, material and information flows, as well all the process data relevant to the value stream required to achieve the daily output, are identified and represented.
Supply shortfalls and “Bottlenecks” are identified and transparently shown in the above mentioned forms of mapping.
The distinction between the supply shortfall (small shortage) and bottlenecks (large shortage) is very important.
An important part of the identified waste are stocks, which cannot be processed in the follow up processes. At Services for example that could be open orders that cannot be executed.
An important part of the identified waste stream is inventory that may be stored in the wrong location or quantity, which therefore cannot be processed or been consumed in the follow up processes.
As part of “Services“ for example, a waste source could be open orders which cannot be fulfilled for a variety of reasons.
The following Data will be determined in the case of a Value Stream Mapping
- Lead time (sub-process) = Inventory (before) / Daily output of the upcoming process
- Cycle time = Sum of the Lead Time of all sub-processes
- Value added time = Sum of all pure add-value time shares for one total output
- Process Circle Efficiency (PCE) = value added time / output time x 100%
Further activities in the context of the Value Stream Mapping
- Immediate improvements are being identified (potentials).
- Presentation of the current status = Current State Map (CSM)
- Presentation of the desired target status = Future State Map (FSM)