This web page accompanies “Using Process Mapping to Identify Patient Safety Hazards in Micro-Systems” in Quality and Safety in Healthcare. by John Grout

Value Stream Mapping is designed to document manufacturing processes that are to be improved using lean manufacturing methods.  Lean manufacturing methods remove waste and non-value-adding activities from processes so that organizations can produce and deliver the products customers order more rapidly and at lower cost.  Waste and non-value added activities come in a variety of forms:

1.  Overproduction ahead of demand
2.  Waiting for the next step (idle time)
3.  Unnecessary movement of materials
4.  Over-processing
5.  Excessive inventories
6.  Unnecessary movement of people
7.  Production of defective products

The value stream approach to process mapping utilizes the icons shown below.  These icons are very useful to those familiar with the jargon of lean manufacturing.  An explanation of the jargon is not presented here (but is available here)

Multiple flows can be represented using value stream mapping. The icons include manual and electronic information flows, material “push” (schedule driven) flows, and material “pull” (demand driven) flows.

Organizational structures are shown explicitly in the identification of customers’ and suppliers’ organizations and implicitly in process boxes intended to show “one area of material flow,” not individual process steps of that flow.  As an area of flow it would not typically cross organizational boundries.

Traditional logical operators, decisions, loops, if-then statements are explicitly provided.  However, they are implied in kanban & “supermarket” work-in-process inventory locations. Most of the logic will occur within the process boxes and will not be specifically identifed by the map.  Highly detailed mapping is not supported nor is it the purpose of this approach to process mapping.

An example of a process map for blood bank operations is shown below.  Take special note of the ruler running along the bottom of the map that shows the flow time at each step in the process.:

[Process Mapping] [Flow Chart] [Top Down] [Swim Lane] [Value Stream]