Developing and Implementing Value Stream Maps Through Kaizen Workshops
Obviously, CPC is not a pure technical or service organization and has some similarities to a manufacturing process. So where can you find an example of TPS being successfully applied to less repetitive technical or service organizations? The answer is that examples will be hard to find.
You could spend your time looking for such an example or you could follow the Toyota Way of analyzing your own situation, developing innovative solutions, and applying lean in your own way. As Cho’s quote in The Toyota Way says, “We place the highest value on actual implementation and taking action.” The first action to take on the road to improvement of any complex service operation is to create a macro value stream map of the entire system.
A proven method used in lean manufacturing is value stream mapping, which was adapted by Mike Rother and John Shook (1999) from Toyota’s material and information flow diagrams. The value stream map captures processes, material flows, and information flows of a given product family and helps to identify waste in the system. Value stream mapping evolved from a tool Toyota now calls the “material and information flow diagram” that Taiichi Ohno’s operation management consulting division used in helping manufacturing suppliers learn TPS. It was the best place to start for suppliers to understand their current situation so they could then map a future state vision that included kanban, production leveling, changeover times, etc. Processes are represented as boxes. Arrows connect the boxes. In the original version, tombstones (for dead material) represent inventory between processes. Overall, lead time is represented and broken into value-added time and non-value-added time.
Even though there are no physical transformations for many service and business operations, one can easily modify this methodology by making more of an “information flow diagram.” Morgan (2002) developed a version that effectively maps product development value streams . The mapping was modified to capture such critical things as decision points, feedback loops, and project review events (hansei events). The events are placed on a project timeline, showing when events take place. Since different organizational functions come into play at different times, the processes are arranged by the function responsible for them, for example “body engineering” and “die-processing” in the diagram. Like value stream mapping for manufacturing, boxes represent processes and triangles represent inventory. Inventory in this case is information waiting to be processed. The hours of queue times are shown in boxes beneath the “inventory” triangles between processes. The processes have some key indicators like the task time (TT), time in system (TIS), and the value ratio of value added to total lead time (VR). Many wastes are represented on the value stream map. In addition to the queue times, we see engineering changes (e/c), rework, and time resolving various issues that result from not doing things right the first time. The cross-hatched arrows connecting processes depict that everything is “pushed” onto the next process in batches.
Service processes are often complex and involve hundreds or thousands of activities. If you try to map everything all at once, it leads to a mess. However, by developing a big-picture, macro value stream map of the current system, you bring everyone together to agree on all the waste in the processes. A macro-future state map can then identify the big picture version and help identify where the biggest opportunities are for reducing waste in the value stream. From this you can identify the most obvious five to 10 high-level phases to work on in great detail to begin to eliminate waste. For example, a shipbuilder created a macro value stream map for the detail design phase for a class of ships. While the overall process seemed too overwhelming to improve, it identified seven subprocesses that were relatively repetitive and therefore perfect candidates for improvement, such as performing engineering analysis. Once you have identified repetitive and manageable processes, an organization is ready to get the maximum return from any kaizen effort. It is here that you can get your team’s hands dirty improving processes on a more detailed level.
The more detailed subprocesses can then be worked on in a project format and using kaizen workshops to blitz activity in short periods of time. The kaizen workshop is one key tool for change in any service organization. I describe here a format that my associates and I have successfully used many times to illustrate the issues and what you can accomplish. The workshops are typically one-week events where participants analyze the current process, develop a lean vision for the process, and, most importantly, begin implementation.
Participants in the event must include the manager responsible for the process being improved (“process owner”), who is the team leader of the event, along with the people who actually do the work within the process. It is also advisable to include customers and suppliers of the process in the event. However, whenever possible, you should limit the team size to no more than 15 people, to keep the workshop discussions and implementation manageable. There are three phases to a kaizen workshop: preparation, the actual workshop, and sustaining and continuous improvement after a workshop. We will discuss each of these.