However from observation, certain problems occurred with the
SPS implementation. The information required for ordering and
supplying parts was only available in the filing system. The person
in charge had to trigger the vehicle information manually from the
MES on an hourly basis. The shopping man in the supermarket area
also had to order parts using a form as a kanban signal. In this scenario,
human error frequently occurred, monitoring of parts ordering
was difficult and the quantities were not always accurate. The
shopping man was also confronted by a large number of parts
required for variants that did not correlate with the AIS provided.
The excessive number of parts on the racks appeared congested
and messy. This situation further raises the difficulty for the task
of the shopping man.
On the assembly line, the assembly operator found that the
wrong parts had been put on the SPS trolley when the parts arrived
at the workstation and therefore, the assembly operator had to
wait for replacement parts. Parts shortage may occur due to a late
delivery from the suppliers.
According to this situation, several conditions must be considered
to solve the problem. We used the Five Why Analysis
approach to determine the root cause of the problems as presented
in Table 1:
Consequently, depending on the analysis, it is important to
structure an efficient parts supply in the supermarket area with
the correct information. A discussion was held with other departments
to establish the best strategies for overcoming the issues
of parts supply. Three improvements were selected to solve the
problems that arise in the supermarket area: (1) synchronized
parts supply (2) e-kanban system and (3) Synchronized Supply
Sheet (SSS) for the door assembly line. Section 4 discusses the
improvements in further detail.