Supply chain problems often sit between functions rather than inside a single department. A purchase requisition waits for approval, a warehouse receipt is not posted, an invoice cannot match, or a shipment sits because documents were not ready. Process mapping makes these handoffs visible.
A process map is a visual representation of how work actually moves from a defined start point to an end point. It can show activities, decisions, handoffs, inputs, outputs, delays and responsibilities, allowing teams to understand the current process before attempting to improve it.
Why Process Mapping Matters in Supply Chains
- Shows where work waits between departments.
- Reveals duplicate approvals and non-value-added steps.
- Identifies process bottlenecks and rework loops.
- Clarifies roles and ownership.
- Links process steps to KPIs and controls.
- Creates a common view before automation or ERP changes.
- Provides an input to risk tools such as FMEA.
ASQ identifies flowcharts as a common process-mapping tool and notes that they can be used to understand, communicate, document and improve processes, including the identification of bottlenecks, delays, errors, duplication and excessive handoffs.
Common Types of Process Maps
| Map Type | Best Use |
|---|---|
| Basic flowchart | Show activities and decisions in sequence |
| Swimlane map | Show handoffs between functions, departments or systems |
| SIPOC | Define the high-level process boundary, suppliers, inputs, outputs and customers before detailed mapping |
| Value Stream Map | Analyze material/information flow, lead time and waste in Lean improvement |
| Current-state map | Document how the process actually works today |
| Future-state map | Define the improved process after problems and controls are addressed |
Basic Process-Mapping Symbols
| Symbol | Typical Meaning |
|---|---|
| Oval / rounded shape | Start or end |
| Rectangle | Process activity or task |
| Diamond | Decision with alternative paths, often Yes / No |
| Arrow | Direction of process flow |
| Parallelogram | Input or output |
| Document symbol | Document or record used/created |
| Delay symbol | Waiting or queue |
How to Build a Supply Chain Process Map
- Define the problem and purpose. Decide what you need to understand or improve.
- Set the process boundary. Clearly identify the start and end points.
- Select the people who perform the work. Do not map only from policy documents; include the people who execute the process.
- List the actual steps. Capture activities, decisions, systems, documents, queues and exceptions.
- Arrange the steps in sequence.
- Add ownership and handoffs. A swimlane structure is useful where several functions are involved.
- Validate the current state. Walk through a real transaction or process example to confirm that the map reflects reality.
- Measure the process. Add cycle time, waiting time, error rate, volume, backlog or other useful performance data.
- Design and control the future state. Remove waste, simplify handoffs, assign controls and define how improvement will be measured.
Example: Procure-to-Pay Process Map
A high-level procure-to-pay flow could be represented as:
Requirement → Purchase Requisition → Approval → Purchase Order → Supplier Confirmation → Delivery → Goods Receipt / Service Entry → Invoice → Match / Exception Resolution → Payment
A detailed map would then show decision points and exceptions. For example:
- Is an approved supplier or contract available?
- Is the requisition within the user’s approval authority?
- Did the supplier confirm the required delivery date?
- Does the received quantity match the PO?
- Does the invoice match the PO and receipt within tolerance?
- Who owns each exception when the answer is “No”?
If invoice processing is slow, the map may reveal that the real problem began several steps earlier—for example, late goods receipt, incorrect PO price or unclear service acceptance.
Example: Warehouse Receiving Process
Vehicle Arrival → Check Appointment / PO → Unload → Count → Inspect → Exception? → Accept / Quarantine → Post Receipt → Put Away → Close Receipt
Useful data on the map could include dock waiting time, unloading time, quantity discrepancy rate, inspection failure rate, receipt-posting time and put-away cycle time.
What to Look for When Analyzing the Current State
- Waiting: Where does work sit without being processed?
- Handoffs: How many times does responsibility move between people or systems?
- Rework: Which steps are repeated because information is incomplete or incorrect?
- Approvals: Are approvals necessary, risk-based and at the right level?
- Manual entry: Is the same data typed into more than one system?
- Exceptions: Is there a clear owner and resolution path?
- Controls: Which controls prevent errors and which merely detect them later?
- Customer impact: Which process failures affect availability, service, cost or compliance?
Current State vs Future State
The current-state map should document what happens today, including workarounds and delays. It should not be drawn as the procedure says the process ought to work.
The future-state map describes the process after agreed improvements. Typical supply-chain improvements include fewer approvals, clearer ownership, automated data transfer, supplier portals, barcode scanning, exception-based workflows and better master-data controls.
KPIs to Add to a Process Map
- End-to-end lead time
- Touch time versus waiting time
- First-pass yield / right-first-time rate
- Backlog and ageing
- Error or exception rate
- Number of handoffs
- Approval time
- On-time completion
- Cost per transaction
- Customer or supplier response time
Common Process-Mapping Mistakes
- Mapping an entire supply chain at such a high level that no problem is visible.
- Starting with a future-state idea before documenting the current process.
- Leaving out exceptions and rework.
- Allowing one expert to draw the map without the people who perform the work.
- Focusing on shapes and software rather than the process problem.
- Automating a poor process instead of simplifying it first.
- Failing to connect improvements to measurable KPIs.
Process Mapping, SIPOC and FMEA
These tools work well together. SIPOC defines the high-level boundary and major inputs/outputs. A process map then documents the detailed flow. FMEA can use those process steps to identify what could fail, the effects, causes and controls.
Interview Question: How Would You Improve a Process?
A strong answer is: I would define the process boundary and objective, map the actual current state with the people performing the work, validate it with a real transaction, add performance data, identify delays, rework, handoffs and control gaps, then design a future state and measure the change with agreed KPIs.
Related SCMANA Guides
Reference
American Society for Quality (ASQ), Flowchart / Process Flow Diagrams & Maps.
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