Creating a value stream map is best completed by a small (usually less than 8 people) Multi-functional team that represents the key functions involved in the end-to-end flow. In a manufacturing flow, a value stream map team would normally involve Manufacturing operations, production planning, Quality control, purchasing, customer service, sales and supply chain. Other functions such as finance and engineering can be included depending on your structure and business needs. Value stream map team members need to have a good understanding of the detail of their own process, but also include individuals with the authority to make changes to the process.
Once you have formed the team/s, you need to decide what you are mapping. This is often done using a “product family matrix”. This is a chart that groups your different products according to the steps that they flow through. All the products that flow through the same or similar process steps are grouped together and called a product family. Typically, you will need to complete one value stream map for each product family. The product family matrix would also include customer data such as the volume of products sold, product mix, order sizes and service requirements such as lead time, etc
You also need to define the scope of the value stream. This includes where the value stream will start and finish (usually the minimum is from receiving of raw materials to shipping) and what you will include in the information flow. Information flows can become very complex so you may choose to exclude financial processes, quotations, QC processes or engineering processes if you need to. In this case, you would just focus on the information flow required to fulfill orders and control the flow of product and material through the process.
At PRIMO, we start the mapping process by getting the team together in a workshop, and introducing the concepts of value stream mapping and then developing the outline of the product flow and information flow as it operates now. We call this the AS-IS map. At this session, we would then agree with what data we need on the individual processes and the overall flow to complete the current state map. We would assign individuals the responsibility to gather this data. We then give the team some time (usually one to two weeks) to gather this data.
When we get the team together again to complete the current state map by adding in the process data and calculating the overall metrics for the value stream, especially the lead time. If necessary, it is possible to overlay other metrics on the value stream such as cost, quality and on-time in-full delivery performance at each step.
Improving Your Value Stream
Once you have completed the current state map, the next step is to work out how you can improve the processes. This is called the future state map (Could-Be model). Creating the future state map involves several steps and I won’t explain them in detail here, but they include:
• Calculating the rate of customer demand or take time.
• Determining the finished goods strategy.
• Working out if you can eliminate processes or combine multiple processes together into a single process with a one-piece flow.
• Where you cannot combine processes working out how they can be connected.
• Determining the point that will be the pacemaker for your process.
• Determining the pitch or planning interval for your process.
• Calculating the overall metrics for your value stream map including the new lead time,
inventory levels and the performance level that needs to be achieved at each process.
As you develop your future state map you will highlight several changes that need to be made to your process. You will also highlight areas where process performance needs to be improved if you are to achieve the future state map goals. These changes and improvements need to be captured. Aim for a future state that can be implemented in 6-12 months. This means that
changes that involve capital investment, major IT changes or new technology that has not been developed yet, probably need to be left for a future value stream.
Finally. you need to develop an action plan to determine how your future state map will be implemented. This will include the timing and resourcing of all the improvements and changes you highlighted in the future state map. The company will need to provide appropriate resources for this.
Once you have implemented your future state map, it becomes your new current state map and the improvement process starts again – CONTINUOUS IMPROVEMENT PROCESS.
Some Common Mistakes
I see some common mistakes made in creating value stream mapping. These can eliminate many of the benefits of developing value stream maps. These include:
• Not going from dock to dock: The real value of a value stream map is that you map your end to end flow, cutting across organisational boundaries. This is how your customer experiences your business. Often, I see attempts to value stream map
“departments” within a business. However, waste usually sits at the interfaces between departments and optimising one department can often create waste in other parts of the flow. It might be easier and avoid corporate politics just to map your own area, but it is probably a waste of time and denies you the main benefits of value stream mapping.
• Failing to define processes correctly: A process starts and stops when the flow stops. This usually means that information or a decision is required before the flow of value can continue. As a result, a single process can include many tasks, provided that, once the sequence of tasks is completed, it can continue without the need for further instruction or information. For example, an assembly line is usually only one process on a value stream map even though it might include dozens or hundreds of tasks performed by many people. This is because once a product starts on the assembly line it will continue all the way through the line without the need for further information or instruction. Likewise, a relatively minor single task can be a process if it breaks the flow. For example, a Quality check may break the flow if the product cannot move onwards until QC approval is given.
• Mixing up Line Balance Charts and Value Stream Maps: Some people will say they value stream map a single work cell. For the same reason as I explain in my comments about not going dock to dock, a map of a single work cell is not a value stream map.
More likely it will be a line balance (yamazumi) chart that is used to balance the work in that work cell and standard work sheets to define the timing, sequence, content and outcomes of the work in that work cell.
• Using Incorrect Information in the Current State: In the world of IT we say, “garbage in garbage out”. The same applies for value stream maps. If you make guesses about what your process metrics are, what your customer needs are or poorly define your value
stream map boundaries you will end up with a current state map that does not reflect reality or is incomplete. Then when you go to create your future state, you are likely to come up with recommendations that cannot be implemented or are not optimal.
• Narrowing the Scope Too Much: You want your value stream map to have a significant impact on your business and therefore I suggest using the product family matrix method described above to define broad product families. Choose the product family that has the most impact on your business to map first. It is much easier to adjust the flow of minor products to fit around your major products than visa-versa. There is a school of thought that you should choose just one product to map. I think this approach is neither necessary or effective. Usually a single product is only a small proportion of your total operation. As well, you are likely to find that the changes you want to make for that product cannot be implemented because of the impact on other products.
• “Brainstorming” to Develop the Future State: On the face of it this seems like a good way to go. Ask round the table, get everyone to write up ideas or mind map your way to a future state. The problem with this is that it is usually a recipe for more of the same.
Participants will most likely push the agendas they have always pushed and the ideas will be constrained by the current state of knowledge. It is a good idea to get the team to highlight obvious improvements when the current state is complete. However, creating a true future state is a structured, step by step process as I describe above. Following those steps will take your team outside its comfort zone, help to neutralise political agendas and most likely lead to an outcome that is much better than anyone in the team expected.
JAS BAHRA, BA(Hons),MBA,CMC,DipM,DipIM
PRIMO BUSINESS SOLUTIONS
P.S. Grant funding is available for SMEs in the West Midlands to assist with developing and
implementing Process Mapping.