© SCS
THE USE OF PROJECT MANAGEMENT METHODOLOGY AND TOOLS TO
IMPROVE MODEL ASSESSMENT IN SIMULATION STUDIES
Germano de Souza Kienbaum
Laboratory for Applied Mathematics and Computing
(LAC) / Institute for Space Research (INPE)
Av. dos Astronautas, 1758 CP 515
12245-970 São José dos Campos, SP, Brasil
e-mail: germano@lac.inpe.br
Álvaro Augusto Neto
Carlos Henrique Netto Lahoz
Aerospace Technical Center (CTA)
Praça Mal. Eduardo Gomes, 50
12228-901 São José dos Campos , SP, Brasil
e-mail: alvaro@comp.ita.br; lahoz@iae.cta.br
KEYWORDS
Project Management and Control, PERT Technique,
Activity Cycle Diagrams, Discrete Event Systems.
ABSTRACT
The simulation model assessment comprises the design of
experiments and model output analysis and it is a difficult
task to be accomplished in simulation studies. The design
of experiments is usually directed towards the
identification of the bottlenecks and alternative strategies
for model execution, by adding some more resources or
modifying the way some components behave, with the
resulting model changes being assessed individually.
Many cross effects, nevertheless, may appear if more than
one factor is applied and they make it difficult to
determine the benefits of local changes to the overall
performance of a complete production process or sub
process. This suggests that the analysis could be directed
towards sequences of repetitive tasks grouped together in
process segments (production phases), representing
partial/complete construction or assembling operations,
which could be studied and improved in terms of
completion time and operation costs, and would therefore
enhance overall system’s performance. This work
proposes the use of project management methodologies
and tools, based on time and cost management with the use
of PERT-like networks, in the identification and analysis
of these process segments, for improvement of model
assessment in simulation studies. The problem class it
addresses is that of discrete event models of serial
production processes.
INTRODUCTION
The results presented and discussed in this work are of a
preliminary and conceptual nature and they have been
produced in order to set the basis for a more ambitious
ongoing research project. The general goal of the main
research project is to develop a comprehensive
methodology, and to design and implement its supporting
tools, aiming at the conduction of simulation studies based
on an integrated approach, originated from a merge of
both process simulation and project management
techniques.
The proposed approach can be thought of as having two
distinct viewpoints: the first one is related with the use of
project management techniques as an auxiliary tool for
modelling and analysis of a problem typical of the process
simulation study area; and the second one is related with
the use of process simulation techniques as an auxiliary
tool for modelling and analysis of a problem typical of the
project management study area.
The methodology, nevertheless, exists only as whole, and
it is based on a modelling concept created by the first
author and denominated Unified Simulation Modelling
Diagrams (USMD). USMD is a modified version of
Project Evaluation and Review Technique (PERT)
diagrams, originated from a mix of both Activity Cycle
Diagrams (ACD) and PERT networks. USMD diagrams
can be used for modelling problems that belong to either
of the domain classes of the two study areas mentioned
above.
This work is focussed on the first viewpoint of the
approach, as implied by its title above, but it does it solely
as a result from the class of problem chosen to illustrate
the creation of USMD, which is an example of a serial
production process, typical of the simulation study area.
Another example of a house construction process, typical
of the project management study area, has also been made
and studied separately as a simulation problem, but it will
not be presented here for lack of space.
The following sections have been devised to explain the
conceptual framework of the proposed methodology and
were divided into: fundamentals of the methodology; its
domain of applicability and limits, a comparison with
other existing methodologies in both study areas, benefits
of the integrated methodology and its tools, and the actual
state of the research. The work concludes with a summary
on the experience gained with the approach and points out
to future research to be carried on the subject.
FUNDAMENTALS OF THE METHODOLOGY
The problem chosen for exemplification of the proposed
approach is that of a hypothetical steelworks, commonly
used as a course project for teaching simulation skills to
post graduation students. Figure 1 shows the layout of the
steelworks, as described in [Kienbaum and Paul 1994].
The Steelworks Problem
The main elements involved in the problem are: blast
furnaces, torpedoes, cranes, steel furnaces and a railway
Proceedings 14th European Simulation Symposium
A. Verbraeck, W. Krug, eds. (c) SCS Europe BVBA, 2002