What is the role of the process flow diagram in Six Sigma?

2 Steps to create a PFD

Creating a PFD requires a systematic approach that involves collecting and analyzing data, mapping and validating the process, and reviewing and improving the diagram. To begin, define the purpose and objectives of the PFD, as well as the scope and level of detail required. Then, gather information about the process from documents, records, interviews, observations, and measurements. Next, draw the PFD using standard symbols and conventions - rectangles for activities, diamonds for decisions, arrows for flows, and circles for connectors. Start with the main process and then add sub-processes and details as needed. Validate the accuracy of the PFD by checking it with process owners, stakeholders, and experts to ensure it reflects the actual process rather than an ideal or assumed one. Finally, review the PFD for clarity, simplicity, consistency, and to eliminate any unnecessary or redundant steps. Use labels, colors, codes or legends to highlight important information or categories.

3 How to use a PFD

Creating a PFD can be used to support various Six Sigma activities and phases, such as defining the problem statement, project scope, customer requirements, and process metrics and goals. It can also measure the current performance of the process, identify key inputs and outputs, and collect data on process variables and indicators. Additionally, a PFD can analyze root causes of process problems, identify gaps and opportunities for improvement, prioritize improvement actions, design and test improvement solutions, simulate the impact of changes, implement changes in the process, monitor and evaluate results of improvement, verify sustainability of changes, and document and standardize the new process.

4 Examples of PFDs

To illustrate how a PFD can be used in Six Sigma, here are some examples of PFDs for different types of processes. For instance, a software development process can benefit from a PFD to show the stages and tasks, such as planning, analysis, design, coding, testing, deployment, and maintenance. It can also display the inputs and outputs of each stage like requirements, specifications, code, test cases, bugs, and feedback. This can help you identify and eliminate the sources of defects, errors, and delays in the software development process. Similarly, a customer service process can use a PFD to show the steps and actions involved in providing service to a customer such as receiving a request, verifying information, resolving the issue, and following up. This includes the inputs and outputs of each step like customer data, service options, solutions, and satisfaction. A PFD can help you optimize and streamline the customer service process as well as reduce the waiting time and the number of complaints while increasing customer loyalty and retention. Lastly, a manufacturing process can use a PFD to show operations and activities involved in producing a product such as raw materials processing, assembly, inspection, packaging and shipping. It can also show inputs and outputs of each operation including quality, quantity cost and time. A PFD can help improve and standardize the manufacturing process while minimizing waste and rework while enhancing product quality and reliability.