MUDA: any activity in your process that does not add value. MUDA is not creating value for the customer. In short: WASTE
Type I muda: Non-value-added tasks which seam to be essential. Business conditions need to be changed to eliminate this type of waste.
Type II muda: Non-value-added tasks which can be eliminated immediately.
These wastes were categorized by Taiichi Ohno within the Toyota production system, they are;
- Transport: the movement of product between operations, and locations.
- Inventory: the work in progress (WIP) and stocks of finished goods and raw materials that a company holds.
- Motion: the physical movement of a person or machine whilst conducting an operation.
- Waiting: the act of waiting for a machine to finish, for product to arrive, or any other cause.
- Overproduction: Over producing product beyond what the customer has ordered.
- Over-processing: conducting operations beyond those that customer requires.
- Defects: product rejects and rework within your processes.
- Skills/ Talent: High skilled workforce to do work that can be done with lesser skilled workforce. We can also say this is failure to utilize the skills and knowledge of all of your employees.
- Resources: failing to turn off lights and unused machines
- By-Products: not making use of by-products of your process
Many “lean” initiatives fail to see past the elimination of Muda and believe that the point of Lean is to just eliminate waste. This leads to implementations that initially appear to save money but quickly fall apart and revert as problems such as customer demand fluctuations and supplier problems occur. They have failed to tackle the other forms of waste identified by Toyota (Mura and Muri).
MURA: Any variation leading to unbalanced situations. In short: UNEVENNESS, inconsistent, irregular. Mura exists when workflow is out of balance and workload is inconsistent and not incompliance with the standard.
MURI: Muri refers to Unreasonable, impossible, overdoing and overburdened. It can also be defined as “Asking the unreasonable or impossible.” Any activity asking unreasonable stress or effort from personnel, material or equipment. In short: OVERBURDEN. For people, Muri means: a too heavy mental- or physical burden. For machinery Muri means: expecting a machine to do more than it is capable of- or has been designed to do.
They have to looked in conjunction and not separately. When a process is not balanced (mura), this leads to an overburden on equipment, facilities and people (muri) which will cause all kinds of non value adding activities (Waiting is also an activity!!) thus leads to muda.
To eliminate MURA and MURI larger parts of the system need to be looked upon, not only a process or process step or operation, but at an entire Value Stream. Makigami, VSM or ‘Process Kaizen’ eliminates MUDA.
Muri is caused by:
- Working on processes you are not trained on.
- Poorly laid out workplaces.
- cluttered workplaces.
- unclear instructions.
- Lack of proper tools and instructions.
- Fluctuating demand.
- Lack of proper maintenance.
- Unreliable processes.
- poor communication routes.
Peter Schilling suggests:
1. Design the system with sufficient capacity to fulfill customer requirements without overburdening people, equipment, or methods (MURI.)
2. Strive to reduce variation/fluctuation to a bare minimum.(MURA)
3. Then strive to eliminate sources of waste!(MUDA)
BUT REMEMBER: Quality first, then cost – first stop shipping scrap.
When takling with these 3 we should:
- Take a careful look at your Mura and your Muri as you start to tackle your Muda.
- Ask why there should be any more variation in your activities then called for by customer behavior.
- Then ask how the remaining, real variation in customer demand can be smoothed internally to stabilize your operations.
- Finally ask how overburdens on your equipment and people — from whatever cause — can be steadily eliminated.
Example of Muri in Services: Incomplete information in ticket by frontline like issue type and user appointment details. Because of which 2nd line called back the user but the call was unanswered as user was not expecting call at that time. Only after multiple attempts 2nd line was able to resolve the issue and end of the shift, 2nd line was not able to meet their resolution goal and now have to hurry up to deliver minimum expected throughput.
Example of Muri from Health Care:
A Team Member’s task is to change linens. This task is routine. She goes to the storage area for linens on her floor, and finds none. She goes to another floor, and perhaps another, and ultimately finds the linens she needs, then returns to the task she was trying to accomplish in the first place. (She at least did not have to hire a taxi to deliver fresh linens from the service, as other caregivers reported they had done.)
At the end of the shift, however, manager would wager this Team Member wasn’t able to get everything done. Or she had to hurry to do things. Perhaps the work left undone is now passed to someone else and will disrupt their work. All of this is an example of overburden – asking (or implicitly expecting) Team Members to do more than they should, or more than they can. At the very least, the floor she took the linens from now has fewer than they probably need, and another safari will be launched from that floor tomorrow.
In both the above cases case, the Team Member is implicitly expected to “do what must be done” in order to deliver care. There are no avenues to address, or even call out, the existence of these problems. Calling them out carries at least an implied professional or psychological risk of being branded a complainer, or “not a team player.”
For management, the question is a simple one: Is this task one which you would deliberately design into this person’s work process? If not, then question why it must be done at all. But you can’t just question it. That implies the person doing it is doing something wrong. She isn’t. She is doing exactly what must be done to do the job she was given. Question why it must be done so you can remove the necessity to do it.
Example of Mura: One obvious example is production processes where the manager is measured on monthly output, the department rushes like mad in the final week of the month to meet targets, using up components and producing parts not actually required. The first week of the month is then slow due to component shortages and no focus on meeting targets.