A plan is what, a schedule is when. It takes both a plan and a schedule to get things done.” – Peter Turla
The Japanese word for levelling out the workload is heijunka (平準化). Heijunka is quite a broad term that has been narrowed by the traditional understanding of the interpretation in Toytota – to mean level scheduling.
The definition of Heijunka: “levelling, equalisation, alleviation, harmonisation”.
The principle of Heijunka is incredibly powerful and challenges us to understand the “load/demand” that is going through our processes and what we can do to try to balance it. We want to avoid the peaks and troughs. Imagine that you suddenly have one hundred items going through your process one minute, followed by ten the next. We are trying to avoid this and plan a steady demand.
The concept links directly to the previous principle – create a “steady flow”. Flow is at the heart of lean; a continuous flow of activities without delays happening at any stage of the process. You can learn more about the principle of flow here.
Let’s have a look at some examples.
Think about the checkout queues in supermarkets. During busy periods, the supermarkets increase the number of cashiers available to avoid the overburden and unlevelled schedules. Employees work part-time shifts to help bolster the peak demands. If they didn’t, customers would vote with their feet and go elsewhere. The “less than ten items” cashiers or “self-scanning” are all ways the supermarkets want to improve the management of the flow. The additional benefits are that it will reduce overheads with hopefully increase customer satisfaction increases as well.
A restaurant is a great example. Many restaurants require that you make a booking. The reservation will be made to accommodate your preferred time best, but it will also depend on the number of other diners already booked in at that time. Your reservation will be scheduled.
The idea is so simple – it stops everyone booking at 7:30 pm, all turning up at the same time and then with the kitchen overloaded with long delays and a drop off in quality. We all know from experience that we don’t want to turn up into a restaurant just after a large group has ordered.
Doctors and Hospitals
Think about scheduled doctor appointments. (Obviously ignoring the hour-long average wait as they are always behind their planned schedule).
Airports & Airlines
Other examples are the frequency of flights at specific parts of the day or perhaps the number of flights per week depending on the demand. We can also see scheduling going on with the baggage security lines. The number open will regularly change to accommodate the numbers of passengers. Hopefully anyway!
Check out the reasonably new concept of smart motorways: no hard shoulders but the ability to flex and change based on the number of cars, the flow of the vehicles and accidents. A variable speed limit is a way to balance the arrival schedule of other cars. If any of you has been travelling on the A23 in the UK recently, I feel for you and hope that when the roadworks finally stop, you will all see the benefits.
On a personal level, think about your workload. Are your weeks well scheduled? Without peaks of demands that cause stress, anxiety? Are all your meetings clumped together?
When things are super busy, our quality of focus and production drops. We know it, and it’s the same everywhere – we are just not very good at doing things about it!
So as you begin to identify opportunities for flow and begin to notice the peaks, the burrows, the downtimes, we need to be creative about how we balance the workload. It’s only fair on our customers, on our teams and ourselves.
Remember that “muda” is only one type of waste. It’s quick to understand how Hejiunka can support both Mura (imbalance) and Mura (unevenness).