Innovative Applications of O.R.
SimLean: Utilising simulation in the implementation of lean in healthcare

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Abstract

Discrete-event simulation (DES) and lean are approaches that have a similar motivation: improvement of processes and service delivery. Both are being used to help improve the delivery of healthcare, but rarely are they used together. This paper explores from a theoretical and an empirical perspective the potential complementary roles of DES and lean in healthcare. The aim is to increase the impact of both approaches in the improvement of healthcare systems. Out of this exploration, the ‘SimLean’ approach is developed in which three roles for DES with lean are identified: education, facilitation and evaluation. These roles are demonstrated through three examples of DES in action with lean. The work demonstrates how the fusion of DES with lean can improve both stakeholder engagement with DES and the impact of lean.

Highlights

► We identify theoretically and empirically the complementary roles of simulation and lean. ► The ‘SimLean’ framework provides three roles for simulation with lean in healthcare. ► We demonstrate the roles of simulation with lean through three example applications. ► The fusion of simulation with lean improves stakeholder engagement with simulation. ► The fusion of simulation with lean improves the impact of lean.

Introduction

Simulation and lean are approaches that are rarely discussed together, particularly in the healthcare context. This is surprising given that they have a similar motivation: improvement of processes and service delivery. With the current focus on the efficiency of health services there has certainly been a growing interest in both simulation and lean, albeit that this has been largely along completely separate tracks. In this paper we ask how they might work to mutual benefit. In particular, we explore the role of simulation in the implementation of lean in healthcare. The aim is to improve the impact and engagement of both lean and simulation enabling them to work in a symbiotic relationship in improving healthcare systems. In particular, this paper aims to introduce an innovative and novel rapid approach to simulation.

Over the last decade there has been a rapid increase in the implementation of lean in healthcare. In a recent literature review focusing on the use of process improvement methodologies in the public sector 51% of publications sourced focused on lean, and 35% of the total specifically focused on lean in health services (Radnor, 2010). Indeed, lean in healthcare appears to have become widespread, especially in the USA, UK and Australia (Brandao de Souza, 2009). Where lean is being implemented tangible benefits have been reported such as reduction of processing or waiting time, increase in quality through a reduction of errors, a reduction in costs (Silvester et al., 2004), alongside intangibles such as increased employee motivation and satisfaction, and increased customer satisfaction (Radnor and Boaden, 2008). Chang et al. (2011) show that quality and efficiency can be improved simultaneously in hospitals. However, it is also important to note that many of these implementations have been confined to a single process or ward rather than a complete patient pathway which limits the scope of lean to improve healthcare processes (Radnor et al., 2011).

Simulation has a much longer history in healthcare with regular articles on its implementation appearing from the 1970s (Brailsford and Vissers, 2011). Since the early 1990s there has been a huge increase, numbering thousands, in the number of articles being published on simulation in healthcare (Brailsford et al., 2009a). As for manufacturing, simulation promises many benefits for health applications including risk reduction for changes to processes, cost and lead time reduction, increased customer satisfaction and greater understanding of healthcare processes among their stakeholders (Hollocks, 1992). However, these benefits are not necessarily being achieved with much evidence to suggest that simulation is simply not having the impact it could in the health sector (Young et al., 2009).

So the story of lean and simulation in health seems to be one of unrealised potential to improve healthcare delivery. Within the research and this paper we have attempted to cultivate a symbiotic relationship between simulation and lean by creating an approach of ‘rapid modelling’ within a Lean event. We argue that this has allowed an innovative and novel approach of simulation to be developed whilst also supporting the sustainability of lean. We will first explore the separate roles of lean and simulation in healthcare, outlining their key assumptions and their implementation in the healthcare context. Following this we demonstrate that simulation and lean can be complementary methodologies and describe how the two approaches can be fused through the ‘SimLean’ approach. We briefly describe three examples of SimLean in action before concluding with an evaluation of the approach and an outline of further work on the development of SimLean.

Section snippets

Lean in healthcare

Originating from the Toyota Motor Corporation, lean (also referred to as the Toyota Production System, TPS) is considered to be a radical alternative to the traditional method of mass production and batching principles for optimal efficiency, quality, speed and cost (Holweg, 2007). The history of lean production has been widely discussed, and shall not be recounted here; refer to (Ohno, 1988, Womack et al., 1990, Womack and Jones, 1996, Fujimoto, 1999, Hines et al., 2004, Holweg, 2007) for

Simulation in healthcare

In a similar fashion to lean, discrete-event simulation (DES), which is the simulation approach that this paper focuses on, emerged from manufacturing. The first DES language was developed by K.D. Tocher for the United Steel Corporation in the late 1950s. Useful histories of the development of DES can be found in Nance and Sargent, 2002, Robinson, 2005 and Hollocks, 2006, Hollocks, 2008. Here we will focus on the definition of and assumptions behind DES, and discuss its applications in

A fusion of DES and lean

There is only limited evidence of simulation and lean being used together; see, for instance, Jahangirian et al. (2010). Simulations which are played out manually to demonstrate lean principles for training purposes are not uncommon. For a useful review see Badurdeen et al. (2010). In some cases these are even computerised (e.g. Ncube, 2010), but such ‘games’ are not full DES models and they do not represent the participants’ real system.

A prime use for DES has been for creating a dynamic

SimLean: using DES with lean in healthcare

So, given that there is a clear complementarity of DES and lean and also a positive interest in using DES with lean in a healthcare context, how can DES be used as part of a lean initiative in a healthcare organisation? Based on our understanding of DES and lean, and the responses from the interviews in the hospital trusts, we are able to identify three key roles for DES with lean (Fig. 1): educate, engage/facilitate and experiment/evaluate. These roles roughly equate to activities that would

Discussion and conclusion

DES and lean have a similar motivation – improvement of processes and service delivery. From a theoretical and empirical perspective we have demonstrated that they can be complementary methodologies. They are, however, largely adopted in isolation to one another. The SimLean approach aims to provide a fusion between DES and lean so they can work in mutual benefit. Indeed, SimLean represents a symbiotic relationship between DES and lean making the implementation of SimLean greater than the sum

Acknowledgements

The financial support of the Strategic Lean Implementation Methodology (SLIM) Project (www2.warwick.ac.uk/fac/soc/wbs/projects/slim) is acknowledged. SLIM is funded by the Warwick Innovative Manufacturing Research Centre (EPSRC grant reference EP/G049971/1).

We are grateful for the advice and support of Matthew Cooke, Neil Davis and Ruth Davies, and for the time given by staff at University Hospitals Coventry and Warwickshire NHS Trust, Royal Bolton Hospital NHS Foundation Trust and Heart of

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