Dr Christian Hicks - Research Background
School of Mechanical and Systems Engineering,
Stephenson Building, University of Newcastle upon Tyne, Newcastle NE1 7RU.
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In
1987, I was appointed as a Research Associate at Newcastle University on
an SERC/ACME project entitled "The application of computer aided production
management (CAPM) systems in engineer to order companies". This work,
in collaboration with the NEI Group, involved identifying the characteristics
of engineer-to-order/ make-to-order capital goods companies; the status
of their CAPM systems; common CAPM problems and finally to conduct research
to identify possible solutions to the CAPM problems identified. The first
stage of the work involved conducting a survey of nine companies and used
systems and data modelling methods (IDEF and Entity-Relationship Diagrams)
to describe the systems. This was the first time that a systematic approach
had been applied to investigating CAPM in the capital goods sector. This
work was published in a number of papers in the period 1989-1995.
The
general limitation of these survey and modelling methods is that they provide
static views, which provide only a snapshot in time. They do not provide
a mechanism for dynamically testing alternative scenarios. A novel large-scale
discrete event simulation of a manufacturing facility interacting with
a CAPM system was therefore developed and used to investigate the issues
identified by the surveys. This work made a number of contributions. Firstly,
it was the first simulation model that included the necessary features
to model the complex environments encountered in MTO/ETO capital goods
companies. Secondly, it was the first simulation that modelled the interaction
of a CAPM system with a manufacturing facility. Thirdly, data structures
capable of representing complex products and processes were devised, together
with an efficient simulation algorithm that enables large problems to be
evaluated in a reasonable amount of time; Fourthly, it provided a framework
for a series of designed experiments that provided significant insight
into CAPM issues in ETO/MTO companies. The case studies were based upon
manufacturing data obtained from NEI Parsons. This work formed the basis
of my PhD thesis, papers
4,18,19,20,21,22,23 and 25.
Simulation provides a mechanism for testing and evaluating scenarios.
It does not enable 'optimal' solutions to be identified. Indeed many of
the heuristics used by CAPM systems are known to generate sub optimal results.
Pupong Pongcharoen, in his PhD has developed a planning tool based upon
Genetic Algorithms that enables 'optimum' schedules to be generated that
minimise penalty costs due to earliness and lateness. The GA procedure
proposed by Goldberg has been modified to include four repair procedures
that 'correct' schedules that are infeasible. New genetic operators have
also been developed and tested. This work is based upon the work of Shawn
Hines who developed a graphical Tk-Tcl interface for the simulation model.
Data obtained from Parsons has been used for the case studies. An important
focus of this work has been the identification of appropriate GA parameters
and operators that produce good solutions quickly. Efficient experimental
designs are necessary to investigate the large number of factors concerned.
We have collaborated with Dave Stewardson (ISRU) on statistical matters.
Papers 6,12,14,37,44,45,46,56 and 58 are based upon this work.
The
original simulation modelling was deterministic. The simulation model was
developed by Adrian Wall (PhD) to include stochastic effects based upon
a wide range of theoretical or empirical distributions. This was an important
development as ETO/MTO are subject to a wide range of uncertainties. A
further PhD student Dong Ping Song has developed planning methods that
take into account uncertainties in process times and developed stochastic
search optimisation techniques (papers 8,9,11,35,42,48 and 55). Two papers
have recently been submitted that explore the selection of dispatching
rules in capital goods companys that produce complex products in stochastic
environments.
The
simulation model contains a detailed description of manufacturing facilities.
Methods of performing cluster analysis were developed as a mechanism for
identifying potential manufacturing cells. Hinrichs (MEng) implemented
Rank Order Clustering and Boe and Cheng’s Close Neighbour Algorithm (paper
26). Adrian Wall (MPhil) implemented hierarchical clustering methods
using similarity coefficients and dendograms. Chris Lee (MBA) and Roger
Aubrey (MSc) applied these techniques at Vickers Defence Systems. The problem
with these methods is that the results are often hard to interpret and
it is common for there to be few clusters identified. This is due to the
high component variety and the nature of processes involved in the manufacture
of capital goods. Hinrichs (MEng) therefore applied a Simulated Annealing
algorithm, which was used to generate 'optimal' layouts for Parsons’ Heavy
Machine Shop. Wee (MEng) developed a Genetic Algorithm approach to the
same problem (paper 47 and also the basis for papers 15,54 and 59).
Tony
Wells (PhD) was the Facility Manager at Siemens Semiconductors and was
interested in the layout and configuration of semiconductor plants. His
work is based upon four case-studies undertaken at plants in the UK, Germany,
USA and Taiwan. He is investigating the relationships between plant configuration
performance benchmarks. Tony is now Managing Director of MW-Zander UK and
derives much of his business from this research.
With
the deregulation of the Power Industry there has been considerable restructuring
within the capital goods industry. The reasons and effects of these changes
are described in paper 52. There has been a general shift from in-house
manufacturing towards a concentration on design and assembly, with manufacturing
being outsourced. I have been involved in interdisciplinary work in supply
chain management with Dr McGovern (Business School) in collaboration with
AMEC Offshore, Clarke Chapman, Siemens Power Generation Systems, VA Tech
and Wellman Booth. Papers 2,3,5,7,31,39 and 52 are a result of this
work. This research identified the crucial role that specifications play
in supply chain relationships. This is the subject of further research
supported by the Small Grants Committee. It is hoped that this work will
be of interest to the EDC companies. Some preliminary research on the simulation
of supply chains in the red meat industry was conducted with Professor
Harvey and Dr McLeay in AEFM (paper 32).
The
survey methods used in the early CAPM work have been developed to use business
process analysis (used in papers 3,16,24,31,33,34,39 and 53). This
has been the basis of our work in knowledge management (papers 38, 39
and 51). I was an invited speaker at an EPSRC/ESRC workshop (paper
40). My experience of CAPM systems, systems analysis, business processes
and computing has provided the background to the three Teaching Company
Programmes. Papers 24,33 and 34 are based upon this work. A further
paper has been submitted that explores the shaping of technology by political
processes within the firm. The revenue from the Teaching Company Programmes
was used to support two research associates (Phil Medlam and Shawn Hines)
and one PhD student (Dong Ping Song).
The
work on the development of optimised scheduling methods will continue as
it is necessary to further develop the method to deal with larger more
complex problems. This has several aspects. Firstly, the program code needs
to optimised to reduce the required computation time. Secondly, it is necessary
to develop models to predict the size of the search space for different
problems. The relationships between the complexity of schedules and appropriate
GA configuration will also be considered. The relative performance of Genetic
Algorithm approaches with other methods such as Taboo Search and Simulated
Annealing will be considered. It is also hoped to simultaneously apply
these methods to manufacturing layout problems. This would represent a
significant advance in manufacturing system design. This type of work would
be ideally suited to overseas PhD students. The second aspect of the proposed
work relates to the application and development of these methods for use
in industry.
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Chris Hicks
Home Page This page was last updated on 31st July 2003.
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Dr Christian Hicks, School of Mechanical and Systems Engineering, University
of Newcastle upon Tyne