Chapter III Six Sigma Measure phase
Process Maps and Flowcharts
Process is defined as the set of interrelated steps carried out to develop a product from input to output. Process map is used for visual representation of process for product development using common shapes and symbols. Using process map documentation, six sigma team identifies the flow of input, time to process and output.
It is the significant feature to improve process and risk analysis also interprets the process flow. Flowchart shows individual steps for inputs, decision points and output. It consists of information relevant to costs, setup time, cycle time, inventory, defects classification and probability of defects. Six sigma teams use process map to understand about individual and group goals.
Process maps and flowcharts enable broader perspective of potential problems and chances for improving the process.
Symbols and its used in flowcharts
One step in the process; only one arrow is used.
Decision Box Question is written in diamond box. More than one arrow goes out of the diamond to express the flow based on decision box answer
Symbol for start or end point of the process
Delay or wait
Circle symbol shows link to another flowchart; indicates the flow to other page
Input or output
Another symbol for start or end point of the processo:p>
Another symbol for start or end point of the process
Swim lane is a tool similar to process mapping where multiple departments are shown in the swim lane. A swim lane is arranged with the department and their function in given step.
Basic steps to create flowchart:
1. Build the boundaries of process, input and output for the process
2. Identify the different steps in the process.
3. Develop the sequence of the process steps happen in parallel and involved in charts
4. Draw the flowchart using symbols.
5. Review the flowchart has completed and appropriate for given operation.
Process mapping used to identify the non-value-added steps and minimize the complexities.
Flowcharts are a classical tool used for supervise a process for a given period, also introduce training of new operators or supervisors.
Written Procedures and Work Instructions:
A document provides broad description about root cause analysis, yield improvement and traceability.
Procedures are written to elaborate:
• What are the steps involved during a process
• Why it should be performed.
• Where the process is performed
• When should the process to be started or end
Work Inspection categorizes into
• Who does that?
• How it is done
Factors considered developing a document
1. Effect on quality
2. Risk of customer dissatisfaction
3. Statutory and regulatory requirements
4. Economic risk
5. Effectiveness and efficiency
6. Competence of personnel
7. Complexity of processes
Work Instruction can be documented as:
• Written instructions
• Photographs or videos
• Electronic screen shots /software-driven process steps
In modeling the process, the real problems are converted into Key process output variables. Some of the examples using six sigma concepts are ,
• Cycle time
• Down time
• Inventory Turns
• Customer satisfaction Index
• Market share
• Yield of a process
Process input and output
Input representation the flow of data and materials into the process from outside. Input variables can be inherent where the variable can be controlled or uncontrolled. Some of the input examples are,
KPIV are the input factor in a process which has been estimated to be a source of variability in output of process.
Output is the data and materials flowing out of the transformation process. Some output examples are
KPOV are the factor resulting from output of a business process includes higher level factors and customer satisfaction ratings which are used to measure the effectiveness of business process.
Six Sigma Process Analysis