August 16, 2015

Six Sigma: Measure : 1 Identify Measurement and Variation

Flow Charts Written Cause and Effect (Fishbone) Diagrams Cause and Effect Matrix Definition  Procedures Process Analysis and documentation  Process Inputs and Outputs Benefits of Process Mapping SIPOC  

Process Analysis and documentation
Tools:Flow chart, process maps, written procedures and work instructions

Process Input and Output:Cause and effect matrix, cause and effect diagram

Process Inputs and Outputs

Before a process can be improved, it must first be measured. This is accomplished by identifying process input variables and process output variables, and documenting their relationships through cause and effect diagrams, relational matrices, flowcharts and other similar tools. Key process variables should be measured, using metrics like percent defective, operation costs, elapsed time, backlog quantity, and documentation errors. The process owners are the best source for identification of the critical variables. Once identified, the relationships between the variables are depicted using a tool such as cause and effect diagrams.

Benefits of Process Mapping

•Provides a visual representation of the process

•Allows flexibility in levels

•Demands verification and objectivity–Hands-on exposure to local activities

•Identifies rework loops and redundancies

•Gives insight into bottlenecks, cycle times and inventory

•Serves as a training and orientation tool

•Identifies non-value added steps•Helps identify when and where to collect data

•Identifies where different work teams use different processes

SIPOC process map is designed to be high level process view with4-7 steps displayed

Simon suggests the following steps for the developing of a SIPOCdiagram: 1.Have the team create the process map. A meeting room with wall space can be used to display the process steps. Cards can be used to map out the process before finalizing a map.2. The process may have four to five key steps. How is the raw material or product transformed? 3. List the outputs of the process. What is the end result, product/service of this process? 4. List the customers of the output of the process. Who is the user of the end result of the process? 5. List the inputs of the process. Where do the materials come from? 6. List the suppliers of the process. Who are the key suppliers?7. As an optional step, identify some preliminary requirements of the customers. 8. Involve the team leader, champion, and other stakeholders for verification of theproject.

Flow Charts

A flow chart or process map is useful to both people familiar with a process and to those people that have a need to understand a process, such as an auditor. A flow chart can depict the sequence of product, containers, paperwork, operator actions or administrative procedures. A flow chart is often the starting point for processimprovement. A plot of the steps in the process can generate numerous improvement ideas.

Flow Charts Used to Identify Improvements.

Organize a team for the purpose of examining the process. . Construct a flow chart to represent each process step. . Discuss and analyze each step in detail. . Ask the key question, “Why do we do it this way?” . Compare the actual process to an imagined “perfect” process. . Is there unnecessary complexity? . Does duplication or redundancy exist? . Are there control points to prevent errors or rejects? Should there be? . Is this process being run the way it should? . Can this process be run differently? . Improvement ideas may come from substantially different processes.

Process Mapping

There are advantages in depicting a process in schematic format.The major advantage is the ability to visualize the process being described. Process mapping or flow charting has the benefit of describing aprocess with symbols, arrows and words without the clutter of sentences. Manycompanies use process maps to outline new procedures and review old proceduresfor viability and thoroughness. Most flow charting uses certain standardized symbols (ANSI Y15.3). Computer flow charting software may contain 15 to 185 shapes with customized variations extending to the 500 range. Many software programs have the ability to create flow charts or process maps, although the information must come from someone knowledgeable about the process.

Written Procedures

Obviously, for most operations a procedure can be created in advance by the appropriate individual(s). Consider the situation where a process exists, but has not been documented. The procedure should be developed by those having responsibility for the process of interest. As an example, suppose the results of the interviews revealed the following process to control nonconforming material:

1. The non conformance is discovered.

2. The nonconforming material is segregated from other conforming material.

3. The non conformance is documented.

4. A material review board reviews the non conformance to determine disposition. The possible dispositions are:

4.1 Scrap the part, which ends the part usage and requires no further action.

4.2 Accept the part for use ”as is” or ”as repaired.”

4.3 Rework the part to its original configuration requirement.

4.4 Regrade the part (with customer approval).

5. The actual disposition is made. 6. Finally, the material is scrapped, used ”as is,” reworked, or regraded.

The process sounded simple in generic description, but takes several twists and turns. Documenting the process in the form of a procedure facilitates consistency in the process. The use of a flow chart helps to visualize the sequence of actions. Most critical procedures should have corresponding flowcharts.

Process Inputs and Outputs

Before a process can be improved, it must first be measured. This is accomplished by identifying process input variables and process output variables, and documenting their relationships through cause and effect diagrams, relational matrices, flowcharts and other similar tools. Key process variables should be measured, using metrics like percent defective, operation costs, elapsed time, backlog quantity, and documentation errors. The process owners are the best source for identification of the critical variables. Once identified, the relationships between the variables are depictedusing atool such as cause and effect diagrams.

Cause and Effect (Fishbone) Diagrams

A cause and effect (fish bone) diagram:

. Breaks problems down into bite-size pieces.

. Displays many possible causes in a graphic manner.

. Is also called a cause & effect, 4-M or Ishikawa diagram.

. Shows how various causes interact.

. Follows brainstorming rules when generating ideas.

A fish bone session is divided into three parts: brainstorming, prioritizing, and development of an action plan.

Identify the problem statement and brainstorm the categories in a fish bone diagram. To prioritize problem causes, polling is often used. The three most probable causes may be circled for the development of an action plan. Generally, the 4-M (manpower, material, method, machine) version of the fishbone diagram will suffice. Occasionally, the expanded version must be used. In a laboratory environment, measurement is a key issue. When discussing the brown grass in the lawn, environment is important.

Cause and Effect Matrix Definition

•Relates the Inputsof a Process to the CTQs

•CTQsare scored as to importance to the Customer

•Inputsare scored as to relationship to Outputs