What is process mapping
Process mapping is the graphic representation of the steps, decisions, owners, inputs and outputs of a process, from the first activity to the result delivered to the customer. The map shows how work really happens, so the team can see rework, waiting and steps with no owner.
The most common formats are the flowchart, the swimlane diagram and BPMN. For a high-level view use SIPOC; to measure material and information times, use value stream mapping. This article covers the symbols, a step-by-step method and a worked example.
Process mapping visual map
The map brings together the flowchart symbols and the steps to map a process.
Which type of map to use
Each technique answers a different question. Choose by the decision the map has to support:
| Technique | What it shows | When to use |
|---|---|---|
| SIPOC | High-level view: supplier, input, process, output, customer | Set the scope before going into detail |
| Flowchart | Steps and decisions in sequence | Document a simple process or train people |
| Swimlane | Flowchart with one lane per owner | Find handoffs and waiting between departments |
| BPMN | Standard notation with events, tasks and gateways | Complex business processes or automation |
| Value stream map | Material and information flow with times | Cut lead time in manufacturing |
Flowchart symbols
A flowchart uses a few standard symbols (ISO 5807 covers the subject). In practice, six are enough:
| Symbol | Meaning |
|---|---|
| Oval (terminator) | Start and end of the process |
| Rectangle | Activity or processing step |
| Diamond | Decision with "yes" and "no" exits |
| Parallelogram | Input or output of data, material or information |
| Document | Form, report or record produced |
| Arrow | Direction of flow between symbols |
Simple rules: flow left to right or top to bottom, one entry and one exit per rectangle, and every diamond with at least two labeled exits. Name steps with verb plus object: "Check credit", not "Credit".
How to map a process in 7 steps
- Define the purpose and scope. Where does the process start and end? Use a SIPOC to fix the boundaries.
- Gather the people who do the work. Include at least one person from each step; they know the exceptions.
- Map the "as is", not the "should be". Record what happens today, including shortcuts and rework.
- Walk the process on site. Follow a real order from start to finish, as in a gemba walk.
- Draw the steps and decisions. Start with sticky notes on the wall; move to software later.
- Measure times and waits. Record each step's processing time and the wait between steps.
- Validate and improve. Check the map with the people who run the process, mark the waste and draw the "to be" using a PDCA cycle.
Example: fulfilling a make-to-order job
Fictional example. The process runs from order receipt to shipping. Times in minutes, measured on one order followed from start to finish:
| Step | Activity | Processing (min) | Wait after step (min) |
|---|---|---|---|
| 1 | Receive the order | 10 | 50 |
| 2 | Check customer credit | 15 | 225 |
| 3 | Schedule production | 20 | 400 |
| 4 | Pick materials | 30 | 100 |
| 5 | Produce | 120 | 240 |
| 6 | Inspect | 15 | 60 |
| 7 | Ship | 20 | 0 |
| Total | 230 | 1,075 |
Calculations:
- Processing time: 10 + 15 + 20 + 30 + 120 + 15 + 20 = 230 min.
- Total wait: 50 + 225 + 400 + 100 + 240 + 60 + 0 = 1,075 min.
- Order lead time: 230 + 1,075 = 1,305 min, or 21 h 45 min.
- Flow efficiency: 230 ÷ 1,305 = 17.6%. In other words, 82.4% of the time the order is sitting still.
Flow efficiency = processing time ÷ total lead time
The longest wait is "Schedule production": 400 min, about 31% of the lead time. The map points to the target: before speeding up production (120 min), cut the scheduling queue and the credit check (225 min). For the full lead time calculation, see lead time.
BPMN: when it is worth it
BPMN (Business Process Model and Notation) is a standard notation maintained by the OMG and also published as ISO/IEC 19510. Its main elements:
- Events (circles): start, intermediate and end.
- Activities (rounded rectangles): tasks and subprocesses.
- Gateways (diamonds): decisions and parallel branches.
- Sequence flows (arrows) and lanes inside pools, showing who does what.
Use BPMN when the process crosses several departments, involves events (such as a message arriving) or will be automated in software. For a shop-floor operation, a swimlane flowchart is usually enough. In administrative processes, Lean Office uses the same map to find waste. After mapping and improving, record the result in a standard operating procedure.
Common process mapping mistakes
- Mapping the ideal. A "should be" map hides the real problems.
- Too much detail. Nobody reads an 80-box map. Draw a high level and detail only the critical stretch.
- Doing it alone. Without the people who do the work, the map comes out wrong and nobody adopts it.
- Ignoring waits. Only activities show up; the gain is in the queues between them.
- The map becomes wall art. Without an improvement action with an owner and a date, the map is just a drawing.
- Mixing levels. Do not combine a macro process and a work instruction in one drawing.
Frequently asked questions
What is process mapping?
It is the graphic representation of the steps, decisions and owners of a process, used to understand, document and improve work.
What is the difference between a flowchart and BPMN?
A flowchart uses a few free-form symbols; BPMN is a standard notation with events, gateways and lanes, suited to complex business processes.
What is the difference between process mapping and value stream mapping?
Process mapping describes steps and decisions; value stream mapping adds material and information flow with times and inventories, to reduce lead time.
What are the basic flowchart symbols?
Oval (start and end), rectangle (activity), diamond (decision), parallelogram (input or output), document and flow arrow.
What tool should I use to map a process?
Start with sticky notes and kraft paper on the wall. Then use any diagramming software; the tool matters less than the involvement of the people who do the work.
How do I calculate flow efficiency?
Divide processing time by total lead time. In the example, 230 ÷ 1,305 = 17.6%.
Sources
- ROTHER, M.; SHOOK, J. Learning to See. Cambridge, MA: Lean Enterprise Institute.
- HARRINGTON, H. J. Business Process Improvement. New York: McGraw-Hill, 1991.
- DUMAS, M. et al. Fundamentals of Business Process Management. Berlin: Springer.
- OMG. Business Process Model and Notation (BPMN), version 2.0. Object Management Group, 2011.
- ISO 5807. Information processing: documentation symbols and conventions for data, program and system flowcharts. ISO.
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About the author
Lean Manufacturing & Behavioral Management Specialist
Over 20 years in the automotive and metalworking industries (GM and Dana), Lean Manufacturing practitioner since 2006. SENAI instructor and mentor in Brazil’s Brasil Mais Produtivo program, delivering consulting, training and audits for 50+ companies, combining quality, productivity and people development.
