What is Heijunka?
Heijunka is known as a Japanese tool used in order to balance production. It is also popularly known as production levelling or production smoothing. Heijunka is the process of reducing the Mura or unevenness wherein in turn it would reduce the Muda or the waste. The said technique is important to the development of production efficiency in lean manufacturing and Toyota Production System. It has this goal of producing intermediate goods within a constant rate in order for the further processing might also be carried out into a constant as well as predictable rate.
Indeed, Heijunka is a vital technique in order to reduce waste and improve production efficiency through levelling the fluctuations in performance into the assembly line. Fluctuation would normally occur within the production or through the demands of the customers.
Toyota Production System would use the Heijunka in order to solve the demand through assembling a mix of models in every batch and would ensure that there would be an inventory of product proportional to the variability that is in demand. In addition, the disruption of the production flow would be minimised through ensuring that the components are being sequenced in order to be available into the right quantity and at the right time. At the same time, changeover periods for important processes like die changes into the steel presses are indeed short or most of the time as little as three minutes.
Five Elements of Heijunka
There are five elements of Heijunka and they are the following:
- The interval wherein all products would be produced
- Fixed sequence of the products
- A pre-determined inventory policy
- Variable number of items for every product
- The direction for improvement
Benefits of Heijunka
The biggest benefit that could be observed out of implementing Heijunka would be the stability of the manpower and also the reduction of the unneeded overtime. Based on the current situation, reduction in the inventory level would be due to the control that you will be able to maintain with the use of kanbans.
The consumption of raw materials must also be improved since you would only build which is needed and when it is needed. Building up too much of a certain product as well as consuming components which are needed for another is considered as a thing of the past.
And another major benefit that you might observe with Heijunka would be a reduction of stress levels within the production area. This production schedule must no longer be a guessing game since they would know each day whether how much product is being expected of them and would be able to accordingly plan. And this could go a long way towards improving the morale.
Indeed, there are numbers of advantages or benefits that could be gained by companies that would consider the application of Heijunka. It would be able to service orders without having any problem and also within the committed time frame at the same time offering goods of high quality. And as a result, companies that are both small and large could follow the said management technique.
— Slimane Zouggari