Value Stream Mapping is a proven tool that helps eliminating waste. Well suited for a broad range of industries and processes, VSM is ideal for creating positive organizational changes, developing efficient future states, and producing system-wide benefits in cost, quality, and flexibility.  

VSM, like any tool, must be applied properly to be effective. That means avoiding all the pitfalls that can invalidate the mapping process. Below are seven pitfalls that employees are prone to when developing a value stream map. These pitfalls not only affect the results of a value stream map, but also rob businesses of the system-wide benefits VSM produces.

Applying VSM where there's no product

 To draw a Value Stream Map you need to have a value stream, which is all the activities required to bring a product from "raw materials" into the customer's hands or to provide a service. The objective is to see where waste occurs at the system level and then develop a plan to remove it. Unfortunately, some people try to apply VSM in situations where there is no product or control part, such as in product development processes. There's no repeatable action or control part to follow in these processes, so VSM won't work in this situation.

Following the worker, not the product

Sometimes an observer follows the worker, not the product. The worker stops dealing with the control part and does something else.  The observer, however, follows the worker instead of the control part. Let's say the product in a doctor's office is the patient. When the doctor finishes his exam, the observer should follow the patient, not the nurse who's updating the patient's chart. If the observer follows the nurse, her or she is mapping the nurse's work, not the work being done on the control part, which stopped when the patient went home.

Trying to do a VSM without observing performance

It's difficult sometimes to follow a product through the entire process or to see a service from beginning to end. Perhaps, the process is extremely long and tedious, the product is set aside for days, or the observer needs to complete the Map quickly. Whatever the case, the observer uses engineering standards to fill in the information boxes and predict the project's potential savings. That won't work. You must observe the work being done for VSM to be accurate. You also must observe the product as it's being produced for VSM to be effective. Otherwise, you're creating a process map, not a value stream map.

Doing VSM in the office

Related to the previous problem, this pitfall relies on the information stored in a computer in the office. With so much information on computers these days, it's possible to develop a Value Stream Map without ever leaving the office. While the Map might be technically correct you're missing the chance to see what's actually happening on the floor. Unfortunately, much of what takes place in the day-to-day operations of a business— phone calls, interruptions, and reprioritizations of work—isn't stored on a computer and it affects production time. The observer needs to see what's happening to create an accurate Value Stream Map.

Ignoring shared resources

Most companies have shared resources. These resources—which may be people, assembly lines, or equipment—often support multiple product families. If the observer forgets to identify these shared resources when developing a value stream map, it will be incorrect. Remember to identify the shared resources in a value stream. Forgetting to do so will produce incorrect estimates for things like cycle times. And that in accuracy will affect the map's end product.

Mixing product families

Most firms produce more than one product family. Sometimes, it gets complicated following a single product family because the observer did a poor job of identifying the key product family. This problem is aggravated if the observer also fails to identify shared resources or follows the person not the product. By not identifying the product family, the observer gets distracted and follows the wrong processing path.

Double counting time

It takes time to understand what goes in an information box and what is a processing step. Changeovers usually go in an information box, but what about travel time. The key is separating the actual work involved in completing the product or service from the things that cause inventory to build up. Long changeovers cause inventory to build, but what about long distances travelling. They both must be eliminated because they both cause inventory to build.

These seven pitfalls aren't the only problems that occur with VSM projects, but they are some of the more common ones. By avoiding them you'll create accurate maps that will help cut waste from your processes. More importantly, you'll reap the system wide benefits VSM produces, making the time and effort highly productive.

Peter Peterka is President of Six Sigma us. For additional information on 6 Sigma or other Six Sigma Online Training programs contact Peter Peterka.