When Value Stream Mapping Doesn't Work
Value Stream Mapping is a tool. It isn't a panacea for all the problems that occur in management.
Introduction
The purpose of this article is to plainly state where Value Stream Mapping works, and where it doesn't. Value Stream Mapping is a tool. It isn't a panacea for all the problems that occur in management. Value Stream Mapping has produced true system wide benefits to cost, quality, lead times, and flexibility. We've seen remarkable results, time and time again. Value Stream Mapping is a tool. It isn't a panacea for all the problems that occur in management.
Where Value Stream Mapping Works
Value Stream Mapping looks at the material and information flows for a value stream. A future state map is created that leads directly to an implementation plan. It is a very powerful device for motivating and planning positive change.
To draw a Value Stream Map you need to have a Value Stream. A Value Stream is all of the activities, both value added and non-value added required to bring a product from raw materials into the hands of the customer. When you create a Value Stream Map, you actually walk the production (or office) floor, following the product, and draw a simple visual representation of the steps in the Material and Information Flows. The objective is to see where waste is occurring at the system level, and then develop a comprehensive plan to remove it. The Value Stream Map is based on actual observation, not what you 'think' is happening. It's real, simple, and visual.
You can identify a true Value Stream where repeatable actions take place. A common tool called a product family matrix helps to identify Value Streams. There is actually something called "The Product" to map. The "product" could be a 'control part' such as a letter traveling through the post office, a piece of steel that will be converted to a refrigerator casing, a patient flowing through a hospital, an insurance form traveling through the approval process, or a purchase order traveling through the requisition process. (The 'product' doesn't have to be a manufactured item). In each of these cases, you can glue yourself to the product (so to speak) and record what happens to it in its travels. The focus is on identifying those steps that add value, and those that are waste. When you can actually do this, you will create a Current State Map (based on reality) that will lead to a Future State Map, and Implementation Plan.
Where Value Stream Mapping Doesn't Apply
As mentioned earlier, Value Stream Mapping is a very powerful tool. After making tremendous gains on their shop floor using Value Stream Mapping, some organizations realize this and try to make the tool apply to anything and everything.
Value Stream Mapping Pitfalls
Product Development Processes (or similar engineering design processes)
The steps taken to produce a specification/design are rarely sequential. There's Step 1, Step 2, Step 1, back to Step 3, Step 1, etc... There is no solid dependency - finish 1 step and start the next. For example, you might not know all of the customer requirements before you start your design work - it's a very iterative process. The output is often knowledge. Trying to Map all the nuances in Product Development using a traditional VS Map could drive you crazy, and you'll never get it right! The Information Flow becomes unpredictable, and multi-directional. Using a block diagram or flowchart will get you into trouble, and build-in Waste by design. For Product Development, there is a different Mapping tool used.
Where there is no product to follow
For example, you might want to Map the VS that an accountant uses to add up a column of figures. What is the "control part" that you will follow? You might find that the process is never the same twice (not repeatable). Is this a Value Stream? In this case, a simple flowchart is the way to go. VS maps follow a 'product', and a flowchart describes what people/departments do in processes. Another example would be a daily staff meeting. Would you create a VS Map of a staff meeting process? Not really the right tool. VS Mapping is difficult to apply in non-repeatable processes where there is no 'product' to watch the flow of value. When creating a VS Map, you need a 'control part' to actually follow. The VS has to be repeatable. How can you build a Future State from a non-existent Current State?
Will I see the same Wastes doing Office Mapping vs. Shop Floor Mapping?
The answer is both yes and no. Taiichi Ohno at Toyota identified 7 Wastes that you will see on most shop floors: Overproduction, Waiting, Inventory, Motion, Transportation, Defects, and Over-Processing. You will see all of these wastes in Office Value Streams. In an office environment, you might see additional wastes; scatter, hand-off, discarded knowledge, useless info, wishful thinking, testing to spec., wrong tools, blocked communications. When Mapping in an office - Example: following a P.O. as the 'control part', it is important that you 'see' these wastes and include them on the Map.
Do I have to follow the same 'control part' all the way through the Value Stream?
Suppose that you have a 'control part' that has to go through a bake oven for 18hrs. Do you pull up a chair, and watch that particular item as it bakes? Of course not. As long as the process is repeatable, you can continue with a new control part, right out of the oven - as long as it is part of the same product family, thereby following the same routing.
Does Value Stream Mapping apply to Job Shops?
If the Flow in the Job Shop was truly unique for every single product produced, there may not be an established, repeatable Value Stream in place to create a map. There are other techniques to use in this case. In most Job Shops, an advanced version of the product family matrix can be used to identify common routings through a plant. Once Job Shop families are identified, they can be mapped, and Future States created. Don't implement improvements in one Value Stream that cause major problems in another.
Implications for Value Stream Mapping Training
Value Stream Mapping training is typically conducted over a period of 2-5 days. There should be a mixture of classroom discussion, and practical hands-on mapping in the workshop. This means that the classroom should be very near the workplace, and run during normal production hours so that real mapping can occur.
To get the most out of the Value Stream Mapping exercise, the sponsor and facilitator need to select the product families to map. They need to set the boundaries of the Mapping effort - usually between the four walls of the facility to start with. Then they need to identify a 'control part' that will be followed by the Mapping Teams during the hands-on exercise. This control part might be a subassembly in manufacturing, a letter in a post office, a patient in an emergency ward, a purchase order - but there has to be a real control part that we can actually see during the hands-on Mapping. Guessing what happens never gives good Mapping results. Once the control part is selected, and the class is broken into teams; each team is assigned a product family and control part to Map.
Conclusion
Value Stream Mapping is a very powerful tool that will help you to gain momentum, and get your team going in the right direction. But like any tool, it can be misused. You wouldn't want to hammer a nail with a tape measure. If you need help with getting started we would be pleased to talk to you.