Discovering: The SIPOC Method5 min read

An earlier blog, ISO 9001:2015, looked at the necessity for Risk-Based Thinking. The SIPOC method was a tool described that could help QA teams break down processes and use that data to compare risk vs reward. To do this, a researcher must first know what the SIPOC method is, when it should be used, and how it should be used.

What is the SIPOC Method

The SIPOC Method is a broad strokes investigation of a process to find out exactly what the process is and how it takes place. It collects data to help define the scope of problems that researchers may not fully understand. If a researcher followed the DMAIC method, the SIPOC Method falls in the Measuring category. According to the American Society for Quality, “A SIPOC diagram maps a process at a high level and identifies potential gaps between suppliers and inputs specifications and between outputs specifications and customers’ expectations,” to help researchers determine what all needs improved in a process or system and get them to think in terms of cause and effect.
SIPOC is an acronym for the steps of the method – Suppliers, Inputs, Process, Outputs, and Customers. ASQ will often include +CM (constraints on the system and measures to be used) in their acronym and other Six Sigma leaders will condense +CM to +R (customer requirements).
S – Suppliers – These organizations provide inputs to the process. Suppliers bring the raw materials, information, or technology to a process that creates a product or service for the customer.
I – Inputs – The raw materials, information, or technology needed to complete a process.
P – Process – This is a “high-level” chart that consists of the 5-7 core activities that make up the process. Its main focus is broader, but can be refined using tools like 5-Why or Ishikawa Diagrams.
O – Outputs – These are what the process produces. Outputs are typically products, services, information, or technology.
C – Customers – SIPOC not only refers to external customers who receive the products or services, but also it involves internal stakeholders who use the outputs in a separate process. (e.g. a company creates components of a product and later assembles a final product)
+C, +M, +R – Constraints, measurements, or customer requirements – These are the process measurements or requirements to be used and are usually determined by the customer or regulatory body.

When to Use the SIPOC Method

SIPOC is a clarity tool. QA researchers can use SIPOC when they are investigating a process, for improvement or analysis, to understand how a process works. Processes may need to be improved or evaluated for greater efficiency, to address customer concerns, or assess risk/reward scenarios. This method visually lays out a process so each aspect can be examined.
This method helps break down a process in a manageable way so that others can easily view it and can communicate the process’s makeup effectively. It is also used to clarify aspects of the process that are not readily apparent. (e.g. Who are the true customers of a process? What are the specifications for an input? Or – What are the customer requirements for a product, service, or information?) The method frames the process in a cause/effect structure so researchers can see how each aspect affects the next step of the process. This can help researchers see how the suppliers, inputs, and process affect internal and external customers, and work to eliminate gaps in the process. Gaps can include unwanted or unnecessary inputs/outputs or process steps that do not add value.
The tool itself is can be adjusted depending on the complexity of the process or depth of investigation researchers need to pursue. Lean Six Sigma Principles recommend SIPOC for a “high-level” or “35,000 ft view” approach to determine the basics of the process. Other tools like 5-Why or Ishikawa diagrams may be more useful for in-depth looks at individual issues.

How to Use the SIPOC Method

This method is a visual diagram and needs to be mapped out to be used. The first thing researchers need is a place to record the diagram. Some applications, like Microsoft Access, have useful diagramming tools, or researchers could use a flip chart or a projector transparency sheet. A whiteboard or open wall-space with post-it notes would also work. Whichever platform, the area needs room to add and update functions to accommodate full process visibility.
Next, researchers need to map out the five boxes for SIPOC and additional boxes for +C, +M, or +R. Once the boxes are drawn, begin to fill in the process section. These are the core processes and can take anywhere from 5-7 steps. Next, identify the outputs of the process and the customers/stakeholders who receive those outputs. Researchers can then identify the inputs of the process and the suppliers of the inputs. Lastly, researchers can record the constraints, measurements, or requirements necessary to the process. See below for a Fictitious Bakery example
Once all of the information is laid out, researchers can analyze the process and see where and how various changes will affect it. They can then do a cost analysis and decide if the changes are worthwhile.
The SIPOC Method is a useful visual tool for teams to all be on the same page. Each member can look over the process and see exactly what is happening and when. The team can then define the scope of improvement. This method frames the process under investigation in a cause/effect structure to help researchers pinpoint exactly where improvements can be made or highlight areas that need further investigation. It can also help researchers understand how the inputs, suppliers, and process affect customers and their needs. It also helps identify process gaps and eliminate internal and external waste.