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SCRC Article Library: Associated Technologies: What Should the Professional Supply Chain Manager Know about Six Sigma?

Associated Technologies: What Should the Professional Supply Chain Manager Know about Six Sigma?

Published on: Jan, 18, 2011

by: Zach Breitenbach, MBA ‘03 Manuela Eilert, MBA ‘03

Associated Technologies

Statistical Process Control (SPC) Software

Examples of SPC Programs

p. Since Six Sigma is a methodology that is built upon statistical analysis, the technologies that are used to support Six Sigma are primarily statistical process control (SPC) software packages. SPC software typically has a number of statistical tools built into it that are critical to a Six Sigma company’s ability to evaluate the efficiency of their processes and analyze data. Other software packages are used to assist with project management. These project management packages are intended to guide a Six Sigma project team through the entire DMAIC process and to allow for improved decision-making and process analysis. Six Sigma software applications are crucial to the successful implementation of the process because they provide the ability to inexpensively and rapidly synthesize and analyze complex data.

Statistical Process Control (SPC) Software

The purpose of SPC software is to evaluate the quality of an organization’s operations, in an effort to optimize efficiency. There are numerous statistical and process analysis tools that are vital to an effective Six Sigma program. Prominent Six Sigma author George Eckes identifies ten such technical tools. SPC software packages typically include many of these tools and more.

  1. Critical to quality (CTQ) trees
  2. Process maps
  3. Histograms
  4. Pareto charts
  5. Process summary worksheets
  6. Cause-effect diagrams
  7. Scatter diagrams
  8. Affinity diagrams
  9. Run charts, and
  1. Control charts (8)

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A CTQ tree is a tool that is used to define the phases of Six Sigma. The tree is used to brainstorm and confirm all of the customer requirements associated with the process that is being improved (8).

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A process map, or flow chart, is also used in the define phase. It is a pictorial representation of the all of the steps that are currently required in the process that is being targeted for improvement (8). Five key items are illustrated: who supplies the process, what inputs are needed, the name given to the process, the output from the process, and the customers that depend on the process (8). Ultimately, it is used to plan out and illustrate how a process should be implemented.

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A histogram, used in the analysis phase, is a graphical way to summarize the distribution of a continuous set of data (8). This tool is useful for helping you to visualize the way data points are spread out and the frequency with which an event occurs in a set of observations (8).

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A Pareto chart, also used in the analysis phase, is best used to evaluate data. It is named after a famous Italian economist, Vilfredo Pareto, who showed that 80% of the world’s wealth was owned by just 20% of the population. This tool alerts Six Sigma teams to such instances of disparity. It is a graphical way to capture the relative significance of how sets of data differ and allows for functions such as ranking problems by their degree of frequency or severity and comparing the number of problems that arise in various areas of operations (8).The chart can also aid in evaluating the before and after effects of a change that was made to a process.

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A process summary worksheet is an analysis tool that functions as a sort of “roll-up” of the process map by identifying which steps in the process add value and which ones do not.8 Those steps that are determined to be non-value-adding are further categorized.

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A cause-effect diagram, used in the analysis phase, is aimed at identifying a number of possible root causes that could lead to problems in a process (8). These diagrams are a valuable resource to turn to when problems arise in a process and must be resolved.

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The scatter diagram, another tool used in the analysis phase, is a plot of multiple data points used for illustrating the relationship between two variables. After ideas have been identified in the cause-effect diagram, the scatter diagram uses the available data to test those ideas. Patterns of data points can validate theories the team has about root causation and cause-effect relationships (8).

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An affinity diagram is used in the improve phase and is the result of a creative brainstorming session in which a group gathers and organizes ideas. These ideas are then used to structure and analyze a complicated process or problem (8).

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The run chart and control chart are used in the control phase. After the histogram and Pareto chart capture a “snapshot” of the process, the run chart acts like a “camcorder”, showing how some aspect of the process changes over time (8).

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Then, a control chart takes the data from the run chart and establishes what are known as the upper and lower control limits. Control limits are defined as “the expected limits of variation above and below the average of the data” (8). If a data point falls outside of the range of the control limits, there is a problem that needs to be addressed.

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h2. Examples of SPC Programs

One example of an SPC program comes from Minitab, a recognized leader in statistical analysis software. Minitab has recently introduced the Minitab Quality Companion (9). This SPC application integrates many of the aforementioned statistical tools. Among those tools are process maps, cause-effect diagrams, affinity diagrams, CTQ, and FMEA (Failure Mode and Effects Analysis) (9). While not included among Eckes’ top ten tools, FMEA is a useful addition. It identifies potential weak points early in the development of a process and is a proactive approach to planning for and preventing problems before they arise (10).

There are other software packages that are geared toward facilitating Six Sigma project management. One project management application that has recently garnered a great deal of attention is Microsoft’s Accelerator for Six Sigma. Accelerator for Six Sigma is an integrated Six Sigma project management tool that capitalizes on some of Microsoft’s previous applications and allows companies to make more efficient use of Microsoft’s current software, such as Project, Office, and Visio (9). Accelerator is designed to interactively lead a Six Sigma project team through the DMAIC process. In terms of cost, Microsoft has agreed to distribute this application free of charge. However, the underlying strategy is that Microsoft requires the users to purchase the software applications that benefit from the Accelerator (11).

Instantis’s Six Sigma Project Lifecycle Management Solution 2.0 (SSPLM 2.0) is another relatively new project management tool entering the market. SSPLM 2.0 is focused on the control aspect of DMAIC. With better control of your Six Sigma projects, this application allows Six Sigma success to be replicated throughout the organization (9). As a company’s Six Sigma effort grows and becomes more widespread, SSPLM 2.0 minimizes the amount of administrative overhead in terms of monitoring, running, and evaluating the development of Six Sigma projects.

Although the key supporting technologies associated with Six Sigma are SPC and project management software, other categories of Six Sigma software tools exist as well. Among these technologies are applications that support such areas as manufacturing scheduling, market analysis, preventative maintenance, production and inventory control, and shop floor control systems.

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SCM TopicsSix Sigma

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