Episode B.002 Unevenness or MURA

The 3 Pillars of Lean: Remove Unevenness, Remove Overburden, Remove Waste.

• Unevenness 
• Overburden
• Waste

MURA - the Japanese term for variation leading to unbalanced situations - UNEVENNESS, inconsistency, or irregular demands. MURA exists when workflow is out of balance and workload is inconsistent and not in compliance with a standard. This is about Scheduling and is a senior management function.

1. Level Production - How can we reduce this Mura (unevenness) and level production? Most companies have a predictable demand when viewed over time, even allowing for seasonal fluctuations. We need to smooth this demand to our processes and reduce the fluctuations in production and service. For example, if your demand is 200 on Monday, 100 on Tuesday, just 50 on Wednesday and Thursday and 100 again on Friday, your average demand is 100. This is the rate at which you want to produce, not having everyone working like mad on Monday and relaxing in the middle of the week. We need to look at the Takt time - the period in which each new product/service needs to be completed. We need to reduce the number of rush jobs and just produce at the rate that the customer demands, any faster is just putting unnecessary strain on the system.
2. JIT - Just in Time is the philosophy of producing what the customer wants when they want it without it being delayed or held in inventory; to achieve the elimination of Unevenness. Eliminating Unevenness means we smooth out this demand over a short period to remove the peaks and troughs of customer requirements. We don’t produce based on a raw set of orders but a paced schedule of orders to regulate and trigger flow. This production smoothing or Heijunka is achieved through using tools such as a Heijunka box which is a planning tool to allocate the work to the main production/service areas.

TAKT time is the maximum acceptable time to meet the demands of the customer. In other words, TAKT Time is the speed with which the product needs to be created or a service delivered to satisfy the needs of the customer. The TAKT Time Formula = (Net Time Available for Production)/(Customer's Daily Demand).

A heijunka box is a visual scheduling tool used in heijunka, a concept originally created by Toyota for achieving a smoother production flow. While heijunka is the smoothing of production, the heijunka box is the name of a specific tool used in achieving the aims of heijunka.

Scheduling (The ability to Build to Schedule)

• Actual Production Volume / Scheduled Production Volume:  how accurate are you at scheduling people, equipment, raw materials AND creating customer expectations - what you delivered divided by what you planned over a period of time (weekly, monthly, etc.) - used to determine accuracy of longer forecasts; 
• Actual Scheduled Mix / Scheduled Mix: because resources are finite, scheduling requires using the same people, equipment, materials at multiple locations within a confined time span, how well did you blend several project demands to maximize the use of resources - used to determine accuracy of shorter forecasts;
• Actual Sequence as Schedule / Number of Sequences: once you have made the schedule for sharing resources, it is a comparison between your scheduled mix of resources against.