What is value stream mapping?

How does the Lean Enterprise Institute define it?

The Lean Enterprise Institute describes the method as diagramming steps in material and information flow. It identifies Toyota as the developer of the tool, called there a material and information flow diagram. The stream includes both value-creating and non-value-creating activities.

The team first records the actual current state. It then creates a target future-state map: how material and information should flow. The future map proposes change; it does not establish that the change is already working or all expected savings have been achieved.

To compare the states, record boundaries, data used and how time is measured. Check the conditions behind each assumption. Redrawing the flow does not itself remove waiting or errors; establish the result after the actual change.

How does it differ from an ordinary process map?

A process map can show steps, decisions, roles and cross-department connections. VSM emphasises the whole selected flow, movement of information and material, and waste within and between processes. This is a difference in focus, not a prohibition on an ordinary map following work end to end or including numbers.

The guides discussed give particular attention in VSM to:

• Information: what determines the next action and when?
• Movement: where does work or material pass onwards and accumulate?
• Time: how long does passage through the flow take, and how much is processing?

Do not confuse elapsed time from start to finish with people’s active working hours. Parallel activities and waiting do not automatically add up to labour. State the unit and what was measured so the comparison can be checked.

When is the method useful?

The Lean Enterprise Institute identifies manufacturing as a common VSM setting but explicitly includes other industries. The method may help when the question is how the whole flow delivers an outcome to the customer, and a local improvement in one department could merely move a queue elsewhere.

In a service, you can trace a request, document or job from receipt to delivery of the result. This illustrates a possible question, not a measured client case of ours. Define value for the recipient and why each step exists before calling an activity redundant.

Company size alone does not determine the choice. A detailed process map may suffice for a particular task; VSM may help with dependencies and waiting across a whole flow. The approaches can complement one another. A method’s name does not replace clear scope and checking with those doing the work.

How does it differ from the Expert Review?

The Expert Review records agreed workflows, people, tools and time by step. It does not present itself as Toyota VSM, require its symbol system or offer a formal VSM value classification of every activity. A shared interest in actual flow does not make the approaches identical.

Each report finding links to a checkable row: process, step, hours a week and the source of the figure. Priority follows today’s time cost. That forms a baseline; implementing changes is separate work, with the effect checked afterwards using the same measurement method.

Questions

Sources

• Lean Enterprise Institute — value streams, maps and measurement.
• iSixSigma — comparing process maps and VSM.
• Miro — the focus of the two approaches.

Related reading

• What is process mapping, and why does your business need it?
• When do you need a process consultant rather than your own map?
• The actual process, or the one on paper?