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Value-Added Process Maps
In view of the fact that reduction in cycle times is a primary goal of Six Sigma, the value-added process (VAP) map can be considered one of the most powerful tools in the sigma toolbox. Designed to differentiate between value-adding and non-value-adding activities in a process, VAP maps target waste that manifests itself in the form of time lost on unnecessary or redundant activities.A VAP map is very similar to a detailed process map insomuch as it is used to sequence events in a process. Of additional value, however, is the calculation of time necessary to execute each individual step in the process. The time to complete individual activities is calculated and appears to the right of each task, and the total cycle time is identified.When the process map and corresponding task times are calculated, teams then begin to identify areas that can be refined or taken out of the process. Naturally, as activities are improved or eliminated, the cycle time decreases. When the exercise is complete, the process is pilot tested and eventually implemented full scale. In the case of a VAP map, the improvement can be measured immediately and interpreted as the difference between the original cycle time and the time necessary to complete the new process.Figure 9.4 is a VAP map prepared by an Indian supplier of components and assemblies to the electronics industry. The engineering department of the Indian company is concerned with the design time necessary to deliver components to its customers. It has been taking over six months from the moment the engineers receive a schematic for a new component until a quality product is delivered to the customer. The engineers feel that part of their value proposition should include rapid turnaround from engineering to manufacturing, with a minimum of design changes along the way. Design of a VAP map was the first step in achieving that goal.
Figure 9.4: Value-Added Process Map for Product Design Process
The first observation that can be made about the engineering and design change VAP map is that there is no communication between the customer and supplier. Without any input or collaboration from the vendor, the customer simply delivers a schematic and expects to receive a perfect component in return. From that point, the exchange resembles a protracted game of ping-pong, where the prototype is bounced back and forth for endless design changes. The alarming aspect of this exercise is that the process takes 195 days to complete. In a world where product life cycles are less than six months, this extended cycle time is unacceptable.As the proposed VAP map suggests, if both vendor and customer were to play on the same side of the ping-pong table, they could deliver a component to production in 100 days. Beginning as a collaborative effort in step one, the vendor and customer work together on quality, fit and manufacturability. When Chapter 3, the supplier management aspect of the lean methodology plays a pivotal role in global operations. When the lean mentality is employed in supplier relationships and can be augmented by sigma techniques designed to remove waste from those relationships, the downstream benefits that accrue to the supply chain are appreciable.
