The term “SIPOC” is an acronym for the five components it comprises: Suppliers, Inputs, Process, Outputs, and Customers. A SIPOC diagram provides a summary of all these elements in visual format. Examples of a SIPOC appear below.
To create the diagram, you need to clarify each of the elements for the process that is the focus of your Six Sigma project. The order in which the steps of creating a SIPOC should be performed is largely a matter of preference. Some people prefer to start with Customers and work back, while others like to go in order starting with Suppliers. Still others like to start with the Process itself, then work back through Inputs and Suppliers and forward through Outputs and Customers, as we do in this example.
Start by delineating the start and stop points for the process you are improving. This puts you in a better position to accurately determine that inputs and outputs, and in turn the suppliers and customers. When creating your SIPOC, you do not want to have more than six steps. This is a high-level process map that will serve as the starting point for the detailed process map you will create in the Measure phase of the DMAIC process. At this stage you are not looking to account for variation or decision points in the process, just the basic three to six steps that are always followed.
Determine what you need in order to perform the process; these are your process inputs. An input can be a tangible item such as a machine part, chemical ingredient, or piece of equipment, or it can be an intangible such as technical specifications. It may come from outside vendors, from other divisions within your company, or from another department in your division.
List the sources for each of the items in your Input list. You may find it helpful to visually depict which suppliers provide which inputs.
For a process that creates a product, the primary output is probably obvious. For service-oriented processes outputs may be less apparent. In either case, be sure to account for secondary outputs such as reports and data that result from your process and that other groups or companies rely on.
List the customers for the items in your Output list. As with the supplier list you may find it beneficial to match the customers to the outputs. Remember to consider internal customers as well as end user consumers.
Once you have completed these steps your SIPOC is complete. Refer back to it throughout your DMAIC project as you begin to use other Six Sigma tools that require knowledge of who your customers are, which internal teams will be affected by changes to your process, and which departments should have representation when you are brainstorming potential root causes and potential solutions.