Scheduling of a computer integrated manufacturing system: A simulation study
Abstract: Purpose: The purpose
of this paper is to study the effect of selected scheduling dispatching rules
on the performance of an actual CIM system using different performance measures
and to compare the results with the literature.
Design/methodology/approach: To achieve this objective, a computer
simulation model of the existing CIM system is developed to test the
performance of different scheduling rules with respect to mean flow time,
machine efficiency and total run time as performance measures.
Findings: Results suggest that the system performs much better
considering the machine efficiency when the initial number of parts released is
maximum and the buffer size is minimum. Furthermore, considering the average
flow time, the system performs much better when the selected dispatching rule
is either Earliest Due Date (EDD) or Shortest Process Time (SPT) with buffer
size of five and the initial number of parts released of eight.
Research limitations/implications: In this research, some limitations
are: a limited number of factors and levels were considered for the experiment
set-up; however the flexibility of the model allows experimenting with
additional factors and levels. In the simulation experiments of this research,
three scheduling dispatching rules (First In/First Out (FIFO), EDD, SPT) were
used. In future research, the effect of other dispatching rules on the system
performance can be compared. Some assumptions can be relaxed in future work.
Practical implications: This research helps to identify the potential
effect of a selected number of dispatching rules and two other factors, the
number of buffers and initial number of parts released, on the performance of
the existing CIM systems with different part types where the machines are the
major resource constraints.
Originality/value: This research is among the few to study the effect of
the dispatching rules on the performance of the CIM systems with use of
terminating simulation analysis. This is also significant given the nature of
the CIM systems that are mostly used to produce different parts in varying
quantities and thus do not produce parts on a continuing basis. This research
is amongst the first to study the combined effect of dispatching rule and the
buffer size in the CIM systems where the job arrivals are predetermined and
depend on the completion of the existing parts in the system. A description of
how buffer size and initial part release is related to the performance of the
CIM system under study for the studied priority dispatching rule is also
provided.
Keywords: computer integrated
manufacturing, flexible manufacturing systems, scheduling, dispatching rules,
simulation
Author: Nadia Bhuiyan, Gerard
Gouw, Daryoosh Yazdi
Journal Code: jptindustrigg110030
