Companies planning a new process or searching for ways to improve a current procedure can employ value stream mapping (VSM), a method that graphically highlights areas in the operation that either already add the greatest benefit or stand in need of improvement. Furthermore, rather than a standalone project, value stream mapping in itself can become an ongoing process, to introduce continuous quality improvement within a company’s practice, from the factory floor through customer service to the boardroom.
VSM as a system helps a process team identify waste from a company’s processes by mapping out a procedure from the product’s point of view. The “value” in value stream mapping is simply anything a customer would consider worth having. VSM is related to the model of lean manufacturing, where the goal is to eliminate everything not necessary to the manufacture of a product, from excess raw materials or inventory to extra steps or time built into the process. The VSM team scrutinizes each step or stage in a process to determine what if anything gets added to the final product that brings it closer to what their customers want. If nothing gets added, the step can be further dissected to determine what precisely is wasted in the step, if not the step entirely. The less waste kept in the process, the more productive the process can be.
Toyota gets credit for developing VSM in the 1980s. Chief engineer Taiichi Ohno and his sensei Shigeo Shingo conceived of an ideal operation while observing operations at Ford Motor Company: an assembly system made up of synchronized, contiguous workstations, with no stockpile of raw material or parts. As they analyzed the system in its individual components, they kept questioning and eliminating obstacles obstructing the performance of this “just-in-time” system.
Beyond just improving productivity, engaging in a VSM project delivers a number of benefits to a company. It enables members to rise above a specific stage or step to better understand the entire process--the flow of work, including links across departments. It gives team members (often drawn from various departments) a common language to discuss the operations their company engages in and forces them to critically review what their company delivers to the customer. It causes members to step back and objectively view the company’s processes, by literally stepping through the process from the product’s point of view. And it not only points out waste and its sources, it allows the possibility of redirecting wasted resources to more productive points, bringing even more value to the company’s products and services.
Terms used in VSM relate to a dichotomy of value versus waste. Anything "value added" is a procedure, step, material or sub-assembly that adds something customers consider worth purchasing or brings the product closer to completion. If the process takes up capital resources (material, time, money) and doesn’t add value, it can be considered wasteful. As Toyota spent considerable time thinking about waste, it had specific "waste" related terms: "muda," any activity that does not add value; "mura," or inconsistency, which can be remedied by delivering the right part to the right place at the right time; and "muri" or overburden, which can be alleviated by standardizing workflow. This overarching theme of continually striving for improvement, from the current state to the ideal future state, is called "kaizen."
VSM is a specific tool to improve productivity; as such it does have limits. First, as it takes a product-level ride through a process, it ignores the human element. The tool also is only as useful as its wielders, who must take care to determine exactly what process falls under scrutiny; the more specific the process the better. As noted earlier, VSM has its roots in the automotive industry, a very specific manufacturing process of a very complex product produced in relatively narrow ranges with very high volumes. VSM can get bogged down when analyzing a process with low volumes or that involve lots of customization (all exceptions, no standard rules). Finally, VSM requires a dedicated team with at least some training in the background and specific terminology of the tools, maps and flow charts to be truly effective.
- process flow image by Christopher Hall from Fotolia.com