5S and multiskilled operators

In a Lean plant, we expect to see a tidy, uncluttered shop floor with high visibility as a result of 5S, and skills matrices on performance boards that track the cross training of the operators in the different tasks performed in that shop. 5S and multiskilled operators are both features of Lean that we do not, a priori, consider as linked. But in fact they are, and the feasibility of implementing certain aspects of 5S is in fact contingent on having multiskilled operators.

For example, assume you are running a traditional machining job-shop. You have a turning center, a milling center, a drilling center, a grinding center, etc. In each of these centers, you have a farm of machines performing only one type of operation and working in parallel. Each job follows its own path from center to center, with a document called traveler showing the list of operations with check marks for the operations done to date. And each center has single-skilled operators, usually able to operate just one machine, or a bank of identical machines, as seen in Figure 1, with the orange areas showing WIP locations.

Figure 1. Machining job-shop

If you try to implement 5S in this context, you will be telling a machinist with 15 years on the same machine to put hand tools on a shadow board and label every location. But the machinist knows where everything is, and sees no value in this exercise. The only clear point is that 5S would make it easier for somebody else to take over the job. And since this machinist doesn’t know how to do anything else in the plant, it is not an attractive proposition.

On the other hand, assume you first set up cells in which each job makes a machinist operate several machines, and the cell operators rotate between jobs, as shown in Figures 2 and 3.

Figure 2. Machine shop with cellular layout
Figure 3. Operator jobs in a cell

Then the shadow boards and labels come in handy and are well received. The tooling is shared among several operators, none of whom “owns” any of the machines (See Figure 4).

Figure 4. Labeled tooling positions in a cell

In other words, if you try to have assigned and labeled locations for tooling in a traditional job-shop, you will get nowhere with the machinists. On the other hand, it is indispensable when you operate with multiskilled operators, and they will cooperate in making it happen.