Business Center

SIPOC-Reference Guide

Anna Ryazantseva, Process Improvement Intern
Posted: October 3, 2013; updated April 24, 2018


The SIPOC-R is a method of identifying the value chain in which a process operates. It helps to identify the high-level picture of the components of a process and clarifies the relationships with key customers and suppliers. The SIPOC-R is a good way to determine the boundaries or scope of a project and provides a structured way to discuss and get consensus on a project before beginning work on it.

Some benefits of using a SIPOC-R diagram include:

  • Starts the cause-and-effect thinking of problem-solving
  • Identifies gaps such as inputs we don’t need but receive, outputs that customers don’t want, but receive anyway, and process steps that are completed, but add no value
  • Gathers relevant data that can be useful in building lower level process maps

When to use a SIPOC-R:

  • When first starting to investigate a process to understand the basics that make up the process.
  • When recording collective knowledge about a process in an easy-to-view format.
  • When communicating about the process and its elements.


SIPOC-R stands for suppliers, inputs, process, outputs, customers, and requirements.

  • Suppliers: Systems, people, organizations, or other sources of the materials, information, or other resources that are consumed or transformed in the process.
  • Inputs: Materials, information, and other resources the suppliers provide that are consumed or transformed in the process.
  • Process: Set of actions and activities that transform the inputs into the outputs.
  • Outputs: Products or services that the process produces and the customer uses.
  • Customers: People, groups of people, companies, systems, and downstream processes that receive the output of the process.
  • Requirements: Specifications for the inputs and outputs in a process which are necessary to successfully complete the process from the standpoint of the person(s) who use the inputs or the outputs.

How CDOT Uses the SIPOC-R

There are many ways to fill out a SIPOC-R diagram. Some start at the “suppliers” and work their way to customers and some start with “customers” and work their way back to “suppliers”. At CDOT, a best practice for using the SIPOC-R is to start by identifying the process steps and clearly noting the start and end steps. We then work our way to outputs, customers, output requirements, inputs, suppliers, and finally, input requirements. The steps (and the order of the steps) are summarized in the diagram below.


6. Fill in column "O" with the suppliers of inputs (people, organizations, etc...)


5. Fill in column "I" with the inputs needed to complete the process.


7. Fill in the requirements for the inputs in the process.


1. Fill in column "P" with the process steps. Be sure to clearly identify the start and end steps.


2. Fill in column "O" with the outputs the process produces.


4. Fill in the requirements for the outputs in the process.


3. Fill in column "C" with the recipients/ users of each output.