Value Stream Mapping: Common Errors and Their Results

Lean strategies and Six Sigma are closely related, though there are significant differences between the two methodologies. One critical Lean tactic is to design a value stream map (VSM). It should clearly illustrate how every element - from physical materials to information - is integrated throughout a business process in order to produce a product or service. Of course, mistakes happen in the design stage. When they do, the VSM will fail to generate results that meet the expectations of the mappers.
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<br>In this article, we'll explore three common errors that mappers make when going through the value stream mapping process. If you avoid making the following mistakes, your Lean project will be more successful in identifying inefficiencies and formulating creative improvements.
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<br>#1 - Removing Focus From The Product
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<br>The observer will often stop watching the product, and instead, choose to follow the person who was working on the product. For example, suppose you wanted to study the time required for a package to travel from a warehouse's delivery dock to an adjoining office. If an employee accepts the package at the dock and immediately delivers it to the office, no problem exists.
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<br>But, what happens if the package makes its trek across the warehouse in stages, falling into the hands of multiple employees along the way? If you were to follow the first employee, you would lose track of the package. The time recorded for the package to make its trek would be grossly inaccurate.
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<br>#2 - Relying Upon The Computer
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<br>Most companies that give attention to process efficiency maintain standards on computer files. Those standards will show important metrics that influence lead and cycle time. Unfortunately, mappers are often tempted to use the standards found in those files to design their value stream map. It's a far more appealing option than spending time observing a process. The problem is that the standards may fail to present the entire picture.
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<br>For example, let's return to our hypothetical warehouse. Let's suppose you want to study the time required for an employee to retrieve a requested box. The lead time standards on the computer might detail the minutes required for the employee to walk to the specific area, find the necessary tools, and retrieve the box. But, suppose the employee is also responsible for answering phone calls that arrive in the warehouse. That will impact the retrieval time. If you were to rely solely upon the computer rather than observing the process in person, you may not have known about the phone calls.
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<br>#3 - Failing To Observe The Process Due To Lack Of Time
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<br>This happens often when observers are tasked with creating a value stream map under tight time constraints. For example, executive management may want to see an estimate of proposed improvement savings by the end of the week. To meet the pending deadline, it's tempting to cut corners. Rather than observing a process, the mapper might make estimates based on existing standards.
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<br>As you can imagine, the resulting value stream map will likely be inaccurate. Plus, neglecting to observe the process in question eliminates the possibility of identifying opportunities for improvement.
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<br>Value stream mapping is only as valuable as it is accurate. Without accurate metrics showing lead times for information and materials, the map is practically useless. Sadly, the mistakes I've described above are common. As a result, many Lean improvement projects are handicapped during their early stages. If you intend to design a value stream map, you must observe the process in question and closely follow the product. That is the only way to design a map that highlights areas that need improvement.
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<br>About the Author: This information on six sigma and lean processes is provided by BMGI, a leading education and consulting firm in the <a href="http://www.bmgi.com/about_us/different.aspx" rel="nofollow">Performance Excellence
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