Evaluating Processes with SIPOC Diagrams

Complex lean Six Sigma projects can be more difficult to properly measure and evaluate. To avoid the risk of missing key elements or gathering incomplete data, evaluation teams should employ SIPOC diagramming. This tool allows for the systematic analysis of inputs and outputs within compound processes that may otherwise be missed.

Why Use SIPOC Diagramming?

The SIPOC diagram takes multiple elements of a process into consideration, providing a 'big picture' perspective that is difficult to achieve with less robust metrics. SIPOC is an anagram representing the 'suppliers', 'inputs', 'process', 'outputs', and 'customers' involved. In some cases, customer requirements are added to the diagram to provide even greater detail. There is some similarity between SIPOC diagramming and Process Mapping, but SIPOC generates a larger body of information. This encompassing evaluation method provides the foundation upon which sound lean Six Sigma processes may be developed.

Benefits of SIPOC Diagramming

SIPOC is particularly useful during the initial evaluation phase of the lean Six Sigma process. It provides robust data on more complex projects upon which process improvements may be defined and implemented with confidence.

SIPOC diagramming is extremely useful when some process information is unclear. Issues it may be applied to for clarification include:

  • Determining who supplies process inputs
  • Identifying what specifications are placed on the inputs.
  • Identifying the true customers of the process.
  • Determining the customer's requirements.

Generating a SIPOC Diagram

Creating a SIPOC diagram is a straightforward process. For best results, space should be available for team members to made additions as additional information becomes available during the diagramming process.

  1. Identify the process outputs. Include links indicating instances where an output is sent to multiple customers.
  2. Identify the customers that receive the process outputs.
  3. Identify the inputs required for correct function of the process.
  4. Identify the suppliers of all process inputs. Include links to indicate suppliers of multiple inputs.
  5. Identify the customer's preliminary requirements, including links to indicate requirements that apply to more than one customer. This can and should be verified more formally during the later stages of the evaluation process. (optional step)
  6. Identify the preliminary process requirements. Include links to indicate requirements that apply to multiple suppliers. More formal verification of this information can occur later in the evaluation process. (optional step)
  7. Review this information with lean Six Sigma team leaders, department managers and anyone else involved in the process under study. Revise any information as needed based upon this review.