Prouction smoothing, which also goes under the name of production levelling, or even its Japanese name, heijunka is a method of reducing waste and of driving forward efficiency in terms of production. It is a fundamental part of Lean thinking and was initially introduced in the Toyota Production System and since then has been exported throughout the world.
What Is Smoothing Production?
Smoothing production is a relatively simple concept. If demand is constant, then it is really easy to smooth production or to level it. After all if you know each day, every day, how much you need to produce, then it is really easy to produce what you need.
However, within the real world, it is almost impossible to accurately forecast demand. Demand, by its very nature, fluctuates according to a variety of constraints and requirements.
But if too much of any single item is produced, then this is seen as waste. Conversely if not enough is produced, then this is also wasteful because staff may have to work overtime and this increases costs.
Smoothing production ensures that there are no fluctuations in terms of production. Batches of any given product are made as small as is financially viable so that there is no endless churning out of parts or goods, that simply have to wait to be dealt with in further processes. This is substantially different from the old way where bigger was always, but always seen as best. Now batches are actually very small.
Changeover times, where production is changed from one specific product or part to another are kept as short as possible, so that there is very little downtime in terms of the machines sitting around waiting for use.
In addition, the workforce and the stock levels all have to be geared up to meet the needs that are demanded by smoothing production, so it is very much an approach that is quite radical and even Toyota have limited just how far they have ‘smoothed’ production!
Smoothing can be done either by the product type or by volume; both are quite efficient and both can bring substantial efficiencies and savings.
Specific Advantages
Specific advantages to be derived from this type of system are much more than just about reducing waste. The most specific advantage has to be the flexibility that this system invokes within the company, ensuring that the customer can get exactly what they want, at a specific time that they need it. This ensures that the customer is kept happy and therefore ensures the longer-term financial stability of the company.
Due to the fact that there is no over or indeed under production, there is no risk that such a surplus of items will be made that will never be sold, so general efficiency is promoted.
The general flow throughout the company and its supply chain is ‘smoothed’ and so there are no blips or bottlenecks in terms of the flow, which in turn leads to a company that is more geared towards Lean,
The smoothing out of production also means that there are less very busy times, which need to have temporary staff brought in. There are also less ‘dry’ times, when staff need to be laid off. As a result, there is a stable workforce and because of this stability they are more loyal and committed to the company, than if they were under threat of redundancy. In addition, eliminating the need for temporary staff means that they do not require intensive training, which will ultimately be poor value for money because they will leave in 3-6 months time.
So there are a number of advantages to operating a system of ‘smooth’ production, but it is a process that is intensive and takes time to implement and implementation also has to be done carefully or else it can be less than successful!
