This issue of the Journal of the Operational Research Society is dedicated to ‘Supply Chain Forecasting and Planning’. This is an area that has benefited, over many years, from Operational Research interventions. Traditionally, OR contributions have been mathematical/algorithmic in nature with an emphasis being placed on new estimation and forecasting procedures. Work in this area continues to prosper. However, OR now includes a wide variety of methodological approaches and an expanded scope in terms of the applications considered.
In addition to mathematical models, simulation tools are increasingly being used to study the implications of forecasting and planning for an entire supply chain. Rigorous qualitative methodologies usually reported in the form of case studies may also provide very useful managerial insights in this area. Moreover, there has been increased interest in the role of human judgement in forecasting and the scope for organizational learning and information sharing. Related research into the information infrastructure to support forecasting and supply chain planning is becoming increasingly important, as does the study of techniques to support the Sales and Operations Planning (S&OP) process of an organization.
It is this plethora of potential research contributions and methodological approaches that triggered the announcement of this special issue towards the end of 2008. We were delighted with the response to our call both in terms of the volume and variety of the papers submitted. Thirty-six papers were contributed from all over the world. All papers submitted were of high quality but some were found not to match the scope of the special issue and/or that of JORS. For the remainder of the papers, the most authoritative figures in the respective sub-areas were sought to act as referees. The outcome of this entire process is what is presented in this special issue of JORS: 13 papers that collectively represent the current state-of-the-art in Supply Chain Forecasting and Planning. The papers span from ‘hard’ OR methodological approaches to fully qualitative studies, and from applications at the strategic level of organizations down to the lowest-level of operations. It is our view that the papers set the agenda for further research in this area.
The manuscripts are first categorized into ‘Case Oriented’ and ‘Theoretical’ papers, following the typical organization of any JORS issue. Subsequently, the latter category is further sub-divided into three main thematic areas focusing on the application areas rather than methodological approach.
The first part of the special issue (Case oriented) contains four papers and demonstrates the continuing importance of case-oriented work in this area. Unfortunately, there have not been many such contributions in the academic literature and we hope that the work presented here will provide a stimulus for further empirical research on the viability of theoretical solutions in a real-world setting.
Theoretical papers are organized around the following three areas: ‘Supply Chain Planning’ (four papers), ‘Sales and Operations Planning (S&OP)’ (two papers), and ‘Supply Chain Forecasting’ (three papers).
Supply chain planning is a crucial organizational process and one that may benefit from a wide variety of methodological approaches. Indeed, this first section of theoretical papers contains various approaches to problem formulation and solution development: mathematical analysis, Monte Carlo simulation, System Dynamics simulation and agent-based simulation, demonstrating the methodological richness that is available for further contributions in this area.
There has been a growing interest in S&OP in the last decade and it is important not to neglect the contribution that OR can make through the introduction of appropriate modelling techniques. This part of the special issue does not focus on the S&OP process as such but on novel approaches that may support such a process.
The special issue closes with three papers that address supply chain forecasting. There seems to be a view, in some quarters, that this area has become ‘stale’. We believe the opposite, that supply chain forecasting is open for many further contributions. There may be limited scope for the introduction of entirely new forecasting techniques nowadays. Nonetheless, there is still much to be gained by looking at new approaches to the deployment of existing techniques. For example, capturing the information provided from multiple series, proposing methods that are based on multiple time periods or researching further how judgement may be best exercised in a forecasting context constitute very important additions to the current state of knowledge, both from an academic and practitioner perspective.
Before we close this introduction to our special issue, we would like to thank both the previous JORS editors, John Wilson and Terry Williams, for offering us the opportunity to edit this special issue. John, in particular, worked very closely with us throughout the process and we would like to express our gratitude to him for resolving all the issues that emerged during the editing process. We would also like to thank Sarah Parry for handling so efficiently the many e-mails relating to this special issue. Finally, a big ‘thank you’ goes to all the colleagues who acted as referees for their detailed and timely responses and for contributing significantly towards the improvement of the manuscripts.
We hope you will find the papers included in this special issue interesting and thought-provoking and that they will stimulate your research and inform your practice.