How value stream mapping identifies and reduces waste
This article is the second in a series of three on how to use value stream mapping in your workplace. If you haven’t already done so have a look at part one
and remind yourself of the medical centre example:
The staff member in charge of “finalising” the patient files sits across the office from where the doctors return the files. Each time he finishes a file he gets up puts away the finished file then walks across the office and picks up the next one
After a value steam mapping exercise, the project team noted that the movement across the office creates waste. They proposed that the staff member is relocated to a desk next to the spot where the doctors drop off files. Additionally, a cart on wheels is placed next to his desk. Completed files go into the tub and are filed by a junior staff member at the end of the day.
7 Sources of Muda
Remember that Muda is a Japanese word for waste. Lean manufacturing identifies 7 sources of waste
When a manufactured product is overproduced can lead to further waste through things like:
- extra storage
- wasted raw materials
- capital frozen
- spoilage or obsolecence
Storing more inventory than is needed can lead to:
- waste of space for housing inventory
- waste of rent for storage space
- waste of transportation costs
- spoilage or obsolescence
For example, I used to work for a company that delivered a lot of training. They had hard-copy training manuals printed in bulk by a supplier.
The training was frequently updated.
New pages had to be printed, delivered with the manuals, and replaced by the students. A typical training session would begin with students removing obsolete pages, throwing them away, and replacing them with new pages. This is an example of inventory becoming obsolete which leads to a range of other waste.
Motion waste is the cost of any motion by a person or machine that is not necessary. Our medical clinic example demonstrates this type of waste.
Motion waste can incur costs in things like:
- fuel waste
Defects add costs as they need to be reworked or replaced, may have additional recycling costs, or may be a total loss of raw materials. They delay the delivery of your product or service and additional costs because checking is necessary.
Defects will also incur costs due to unhappy customers
Over-processing waste refers to any step of the manufacturing component that can be deemed unnecessary. Examples include adding features users did not ask for or writing reports that no one actually reads.
In my experience, this is often a source of quick and easy process improvements.
Walk around your workplace and ask people why they are doing a particular task. If no one can give you a sensible answer this might be an overprocessing waste.
Waiting waste is the cost of any step in the process that causes a delayed reaction to the final output. Waiting causes expenses in lighting, heating, cooling, spoilage, obsolescence and wage costs.
Transport waste is similar to motion waste but deals with external transport movement between multiple locations or third-party partnerships rather than internal movement.
In our training manual example delivering the manuals could be considered transport waste.
In the medical clinic, for example, moving files to an offsite archiving facility could be considered transport waste.
The third and final chapter article in the Value Stream Mapping series will walk you through how to run a VSM project at your workplace. Stay tuned!