We are going through a period in which labor costs are rising rapidly. Unbalanced lines, which were not a problem in the past, have now begun to affect production costs directly. In Turkey, as in Europe, labor is increasingly beginning to create a cost at least as great as raw material. If we do not carry out improvement practices very carefully, we will begin to lose our ability to compete.
A very significant part of labor costs is now also the cost created by lines that run unbalanced. Especially in periods when customer demand fluctuates, that is, at times when delays occur less often, these costs become invisible and an atmosphere forms as if there were no problem at all.
If we examine the root causes of imbalance, we arrive at the following results:
- Production labor times not being known, the line generally being planned according to what employees say, and due importance not being given to labor times
- Making theoretical improvements, that is, unbalanced lines forming because the machine is run as fast as possible
- Hidden imbalances forming widely because there is no one-piece flow
- Unbalanced production lines being created through the incorrect use of technological improvements
- Lines being created that run much faster than necessary, or much slower than necessary, instead of working in line with Takt Time
Yamazumi provides the method we need in order to identify these imbalances easily. Of course, to improve the system we need to carry out Kaizen activities, change the content of workstations in order to eliminate the imbalances, and put new configurations into operation. These are obtained by examining the reports provided by Yamazumi. For this, each work step is examined one by one and its time is determined, and thus each station is obtained together with its work-content times. The Yamazumi charts to be created show us a station's time balance with the other stations, so that we can easily find where to intervene.
What needs to be done to eliminate the causes we identified above can be explained as follows.
- Determining production labor times: In many places, cycle time and labor time can be confused. As a good practice, we recommend determining the time by video-recording the work in order to establish the labor time.
- Making theoretical improvements: In many places, topics such as production managers and/or employers running a machine as fast as possible, and then using the time gained on other work, have come onto the agenda. However, experience has established that this is of no benefit at all. It is essential, in terms of reducing work that does not create added value, for the production chain to operate with as few groups as possible and for continuous flow to be created.
- The absence of one-piece flow creates hidden imbalances. When you enter the plant, every employee appears to be producing; however, when you look at the weekly, monthly, or annual figures, it will be seen that very low quantities have been delivered. Employees often say that moving to one-piece flow will slow the work down, or that production will be done with more people. Yet, in a system where labor time decreases through the elimination of work that does not create added value, it is not very meaningful to say that more labor is required. In other words, what is said is one thing and what is practiced is another. The reason for this statement is generally a shortcoming in work management. Moving to one-piece flow ultimately means completing the work steps until one product is finished at a station, and then moving on to the next.
- Technological improvements make machines faster and more efficient. However, as a result of the improvement, imbalances also form between stations. Attention must be paid to this. It is important to use technology in a way that does not create imbalance.
- Takt Time means producing at the rate of sales. The basic target should be to produce what is sold by using fewer resources. Faster production may not mean lower cost. On the contrary, you may cause costs to increase through the use of more resources.
In conclusion, the use of Yamazumi is a method that provides us with a major resource by showing the imbalances in the production chain and the activities that do not create added value. With correct use, significant improvements can be made.