Value Stream Mapping – Page 2

Data Box

A process box is used to indicate the process name and covers one area of continuous flow where products flow without being stored, queued or delayed (or without significant waiting time between steps).

Data boxes are used to carry all data related to a specific process box. Data boxes can also be used to display data and performance information related to inventory, transportation and important suppliers and customers (see below).

Supplier data box Process data box Customer data box
Demand rate (items/day)
Shipping frequency
Packaging size
Actual lead time
Required lead time
Error rate
Order adjustments
Supplier shift pattern
Number of suppliers
Different types of materials
Cycle time (CT)
Changeover time (C/O)
Value-added time (VAT)
Net available working time (NAT)
Production rate (i.e. units/day)
Scrap rate / % defects
Machine uptime %
Processing time
Maximum capacity
Product flow (push or pull)
Overall equipment effectiveness
Number of operators
Number of product variations
Setup time
Batch size
Rework rate
Customer demand (items/day)
Shipping frequency
Packaging size requirement
Actual lead time
Required lead time
Error rate
Order adjustments
Customer shift pattern
Number of customers
Product mix
Transportation data box Inventory data box
Lot size
Transportation time
Number of product types
Distance traveled
Transportation frequency
Amount of inventory
Queue or delay time
Number of product types
Inventory type

How to Conduct a Value Stream Mapping Exercise:

Value stream maps are conducted through the following steps:

  • Establish the team and include people working in the process, process owners and planners.
  • With your team, identify the product and the value stream that needs to be mapped.
  • Physically walk the flow starting from the customer then work upstream through the process.
  • Capture all relevant data and performance information as you walk (e.g. cycle times, schedule requirements, delays and inventory between processes, etc.). Always record what you see not what you are told is normally there.
  • Walk the information flow as well and collect examples of relevant documentation and records.
  • Talk to the people there and listen to their ideas and issues.
  • Draw the map on a large piece of paper using the standard set of symbols. Map what actually happens as opposed to what should happen.
  • Start with the material flow including processes, inventory, delays and transportation. Group process steps where they are linked together.
  • Map the information flow and the secondary processes (e.g. rework loops).
  • Complete the data boxes then add the VSM timeline and any other information you feel is relevant to the map.
  • Identify the non-value added activities, delays, rework, bottlenecks, excessive inventories and other form of waste.
  • Brainstorm how to eliminate waste and improve the process. Ask questions like:
    • Are things done in the right sequence?
    • Does information arrive on time?
    • Can any paper work be eliminated?
    • Are existing systems used in optimum way?
    • Is automation possible?
    • Is information available, reliable and up-to-date?
    • Is information really used in decision making?
    • Are there any quick wins possible through immediate improvements without significant investments?
  • Visualize the ideal state and develop a future state map for where you want to be.
  • Plan and implement actions to achieve the future state.

Example:

The following is an example of a value stream map that was created for a specific product in a product line. Note the timeline that is placed at the bottom of the map which reflects the value added and the non-value added activities of the core process.

Example:

This is an example of a value stream map for a non-manufacturing process (equipment installation).

Further Information:

  • It is important to define what is meant by the future before beginning to develop the future state.
  • VSM tends to display more information than a typical process map. A process map just shows the process as it is. A value stream map highlights the flow of value and suggests improvements.
  • Make sure that customer’s data is directly taken from the customer or from the person who receives customer orders.
  • Transportation should be considered both in terms of how the raw materials are brought in and how the finished goods are sent out. Transportation can be of three types: external (e.g. trucking), internal (e.g. forklifts), and conveying techniques between processes.

« Page 1 – Page 2 »