Lean principles and practices have been widely adopted by many companies since the early 1990s. These companies are now beginning to realise that traditional costing and accounting methods may hinder the lean initiatives that they are implementing. This raises an important question: “Which cost management and accounting approaches best support the newly implemented lean principles and practices?” This paper examines the relative impact of three different management accounting systems on lean manufacturing implementation through simulation modelling with a single performance metric – net income. Three management accounting alternatives included in this study: traditional management accounting (TMA), activity-based costing (ABC), and value stream costing (VSC). This study compares these three management accounting alternatives using process simulation and statistically designed experimental methods. The results demonstrate that VSC appears to provide a bridge between operational views and financial views of lean, which enhances the transfer of information from shop level to management level.

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A comparative analysis of management accounting systems’ impact on lean implementation

Recently, most healthcare organizations focus their attention on reducing the cost of their supply chain management (SCM) by improving the decision making pertaining processes' efficiencies. The availability of products through healthcare SCM is often a matter of life or death to the patient; therefore, trial and error approaches are not an option in this environment. Simulation and modeling (SM) has been presented as an alternative approach for supply chain managers in healthcare organizations to test solutions and to support decision making processes associated with various SCM problems. This paper presents and analyzes past SM efforts to support decision making in healthcare SCM and identifies the key challenges associated with healthcare SCM modeling. We also present and discuss emerging technologies to meet these challenges.

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Simulation and Modeling Efforts to Support Decision Making in Healthcare Supply Chain Management

Purpose: This paper describes a typical Value stream mapping (VSM) application enhanced by the discrete event simulation (DES) to a dedicated tubular manufacturing process. Design/Methodology/Approach: VSM is prescribed as part of lean production portfolio of tools, not only highlights process inefficiencies, transactional and communication mismatches, but also guides improvement areas. Meanwhile, DES is used to reduce uncertainty and create consensus by visualizing dynamic process views. It is served as a complementary tool for the traditional VSM to provide sufficient justification and quantifiable evidence needed to convince the lean approaches. A simulation model is developed to replicate the operation of an existing system, and that of a proposed system that modifies the existing design to incorporate lean manufacturing shop floor principles. Findings: A comprehensive model for the tubular manufacturing process is constructed, and distinctive scenarios are derived to uncover an optimal future state of the process. Various simulation scenarios are developed. The simulated results are acquired and investigated, and they are well matched with the real production data. Originality/Value: DES is demonstrated as a guided tool to assist organizations with the decision to implement lean approaches by quantifying benefits from applying the VSM. A roadmap is provided to illustrate how the VSM is used to design a desired future state. The developed simulation scenarios mimic the behavior of the actual manufacturing process in an intuitive manner.

https://www.econstor.eu/bitstream/10419/188539/1/v06-i02-p0456_532-4700-1-PB.pdf

Simulation guided value stream mapping and lean improvement: A case study of a tubular machining facility

Simulation is an effective method for improving supply chain performance. However, there is limited advice available to assist practitioners in selecting the most appropriate method for a given problem. Much of the advice that does exist relies on custom and practice rather than a rigorous conceptual or empirical analysis. An analysis of the different modelling techniques applied in the supply chain domain was conducted, and the three main approaches to simulation used were identified; these are System Dynamics (SD), Discrete Event Simulation (DES) and Agent Based Modelling (ABM). This research has examined these approaches in two stages. Firstly, a first principles analysis was carried out in order to challenge the received wisdom about their strengths and weaknesses and a series of propositions were developed from this initial analysis. The second stage was to use the case study approach to test these propositions and to provide further empirical evidence to support their comparison. The contributions of this research are both in terms of knowledge and practice. In terms of knowledge, this research is the first holistic cross paradigm comparison of the three main approaches in the supply chain domain. Case studies have involved building ‘back to back’ models of the same supply chain problem using SD and a discrete approach (either DES or ABM). This has led to contributions concerning the limitations of applying SD to operational problem types. SD has also been found to have risks when applied to strategic and policy problems. Discrete methods have been found to have potential for exploring strategic problem types. It has been found that discrete simulation methods can model material and information feedback successfully. Further insights have been gained into the relationship between modelling purpose and modelling approach. In terms of practice, the findings have been summarised in the form of a framework linking modelling purpose, problem characteristics and simulation approach.

Selection of simulation tools for improving supply chain performance

The work presented here is with a view to improving performance of sterilization services in hospitals. We carried out a survey in a large number of health establishments in the Rhone-Alpes region in France. Based on the results of this survey and a detailed study of a specific service, we have built a generic model. The generic nature of the model relies on a common structure with a high level of detail. This model can be used to improve the performance of a specific sterilization service and/or to dimension its resources. It can also serve for quantitative comparison of performance indicators of various sterilization services.

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A generic simulation model to assess the performance of sterilization services in health establishments

Modelling and simulating manufacturing systems often involves several different organisational units This can make data collection difficult and it can be hard to obtain data that allows for the model to be built with a consistent level of detail To investigate the impact of a varying level of detail, a manufacturing system was modelled using different levels of detail The first model was modelled at a high level of detail containing all elements in the system The second model was an aggregation of some of the processes in the system and the third model consisted only of the main processes The experiments performed with the models, aimed at finding differences between models' outputs that originated from the choice of the level of detail The results show that there are significant differences between the models The simulation models used for this paper are made in collaboration with a company in the mobile communications industry and deals with supply chain problems

J.Fredrik Persson

Papers

The impact of different levels of detail in manufacturing systems simulation models