Forecasting and inventory management:
Bridging the gap
Opening session
Aris A. Syntetos and John E. Boylan
Outline
1
Research background
2
EPSRC – EP/D062942/1 (Aris)
3
EPSRC – EP/F012632/1 (Aris and John)
4
Agenda for our meeting
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Research background (…1 of 3)


John’s research with Roy Johnston in forecasting and stock control, with
particular emphasis on intermittent demands
Aris’ PhD under John’s supervision: ‘Forecasting of intermittent demand’
Our work necessitated the clarification of what is ‘intermittent demand’ in
operational terms?
10
9
8
Demand size

7
6
5
4
3
2
1
0
Jan Apr
97 97
Jul
97
Oct Jan Apr
97 98 98
Jul
98
Oct Jan Apr
98 99 99
Jul
99
Oct Jan Apr
99 00 00
Jul
00
Oct
00
Months
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Research background (...2 of 3)

Consequent work in the classification of demand patterns for forecasting
and stock control purposes
Williams (1984)
Eaves and Kingsman (2004)
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Research background (...3 of 3)

Joint work with John Croston resulted in the proposal of a theoretically
sound categorisation solutions, for forecasting purposes only:
 Further work into this area demonstrated the complexity arising due to
the interaction between forecasting and stock control.
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EPSRC – EP/D062942/1

On the development of theory-informed operationalised definitions of
demand patterns

A simulation intensive investigation that aims at the development of
useful, universally applicable, rules for classifying demand patterns

Theory-data loops to reflect the complexity of the problem and the
interaction between forecasting and stock control

We will be talking more about this project later today: Forecasting – stock
control interactions I (Aris and Zied)

This is a 2-year project started last October.

Very fruitful research area: four papers already submitted for peer review

John is contributing as part of the project review team.
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EP/D062942/1 - Industrial collaborators
Brother International, UK
Computer Science Corporation
Valves Instrument Plus, Ltd
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Collaboration for Success through People (CSP)
 EPSRC call under the CSP initiative for expanding the scope of curent
projects through the exploitation of inter-disciplinary opportunities
 Funds were made available for people based activities and exchanges
 That resulted in our joint proposal (Aris and John) that led to our project
 This is a 9-month project with no specific deliverables, other than exploring
and hopefully utilising potential synergies, establishing longer-term contacts
and identifying promising new avenues for further research
 The aim of this project is to bring together the strengths of statistical and
judgemental forecasting with the complementary benefits of System Dynamics
(SD), to initiate a new research agenda for inventory modelling.
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Objectives - EP/F012632/1
The aim is reflected on the following objectives
1.
To explore how statistical forecasting models (which focus on mean demand and
forecast error variability) and System Dynamics (SD) models (which focus on
changes in mean demand) can be integrated.
2.
To explore the effects of judgemental forecasting (or judgemental adjustments to
statistical forecasts) on levels and variability of forecasts and the potential for
their incorporation in System Dynamics models.
3.
To extend this investigation to examine the effect on inventory systems, for a
range of inventory policies.
4.
To examine how SD can be used to inform and educate those involved in
judgemental forecasting.
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Collaborators
Academics
Institution
Expertise
Professor John Boylan
Dr Aris Syntetos
Dr Stephen Disney
Professor Henk Akkermans
Professor Leo Strijbosch
Dr Tarkan Tan
Professor Nada Sanders
Dr S (Vish) Viswanathan
BCUC
Salford University
Cardiff University
Tilburg University
Tilburg University
Eindhoven University
Texas Christian Univ.
Nanyang University
Co-ordination team
Co-ordination team
System Dynamics
System Dynamics
Forecasting/Inventory
Inventory Modelling
Judgemental Forecasting
Forecasting/Inventory
Practitioners
Company
Specialisation
Dr Wolfgang Schutz
Dr Stephan Kolassa
Dr Bob Eberlein
SAF – AG
SAF – AG
Ventana Systems, Inc
Forecasting software
Forecasting software
System Dynamics Software
Reviewers
Professor Paul Goodwin
Professor Brian Dangerfield
Institution
Bath University
Salford University
Expertise
Judgemental forecasting
System Dynamics
Supporters: Zied Babai, Mohammad Ali and Mona Mohammadipour
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Meetings and dissemination
 Physical meetings to be conducted between John and Aris and the other
collaborators during the course of the project
 We have also introduced web-based conference communications in order to: i)
keep the costs down; ii) introduce some flexibility and the possibility for ad-hoc
virtual meetings
 A web-site hosted by the University of Salford has already been created
 We are looking at making this facility an interactive mode of communicating
and posting ideas
 Progressive incorporation of the outcomes of our meetings, research findings
etc
 Any ideas that you may have in improving this facility would be very welcomed
 Dissemination of our work through: System Dynamics Review (Wiley) and
International Journal of Production Economics (Elsevier)
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Initial meeting
 One-hour discussion sessions where the group can be updated on latest
developments, reflecting your perspective and expertise
 Open and relaxed discussions allowing the time for constructive
comments to be made and explore the synergies between the various
areas
 As we are all often working within fairly well defined small research
communities, ‘basic’ questions would not do any harm – on the contrary
they may facilitate a better understanding of the common ground between
us
 Breakfast is served from 07.30 – 08.45 am
 The dinner tonight is at 07.00 pm
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Proposed timetable
Sessions (Tuesday)
Facilitator(s)
Opening session
John and Aris
System Dynamics
Brian
Software perspective (Forecasting)
Stephan
Forecasting – stock control interactions I
Aris and Zied
Forecasting – stock control interactions II
Leo
Forecasting – stock control interactions III
Tarkan
Session (Wednesday)
Facilitator(s)
System Dynamics – Bullwhip I
Steve
System Dynamics – Bullwhip II
John and Mohammad
Concluding session
John and Aris
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Looking forward to an exciting project
Questions …?
http://www.mams.salford.ac.uk/CORAS/Projects/Bridging_The_Gap/
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