Benny Tjahjono

Six Sigma: a literature review

Purpose – The purpose of the work presented in this paper is to capture the current state of Six Sigma as well as to document the current practices of Six Sigma through a systematic literature review so as to extend and update the previous work of Brady and Allen.Design/methodology/approach – The approach to this paper is to answer the questions such as “what is Six Sigma?”, “what are the applications of the Six Sigma?”, “what are the main enablers and barriers to its application?” and “what are the emerging trends?” These questions are used to guide the search of papers from various publication databases even if it is expected that existing literature might not be sufficiently developed to translate each question directly into a finding. The literature is then analysed and the major emerging themes are presented.Findings – Seven key findings (topics on which the views of the authors converged) and two issues (topics on which authors had differing views) have been established. These include the interpreta...

Towards Product-Service Systems modelling: a quest for dynamic behaviour and model parameters

The product-service system (PSS) is an emerging manufacturing paradigm embracing the increased value of offering through the integration of products and services as a basis of competitive strategy. The PSS has various characteristics beyond the traditional product-selling businesses as a result of intense customer interactions and increased service levels. These interactions can further trigger the dynamic behaviour of the system and consequently can cause uncertainties across the whole network of manufacturers and customers. The work described in this paper is part of a research project whose overall goal is to provide the manufacturing system designers with better decision making capabilities to effectively shift their manufacturing businesses from product selling to PSS offering. In particular, this paper aims to capture typical characteristics exhibited by manufacturers who have adopted PSS, to better understand their dynamic behaviour, to have appreciation of the existing techniques and tools for modelling PSS, and ultimately to search for PSS model parameters. The main contribution of this paper is the collation of key model parameters that should be considered for an effective PSS modelling. The paper also identifies strengths and weaknesses within the existing PSS modelling work, and highlights the opportunities for future research agenda.

Lean thinking implementation at a safari park

Purpose – The purpose of this paper is to report on a research project at a safari park in Buckinghamshire, UK. The aim is to introduce lean principles to the park, to enable the park to increase profits through eliminating waste and improving the efficiency of key processes whilst concurrently increasing customer satisfaction. The research is based on a case study approach within the organisation over a period of three months. The project team worked together with management and staff to deliver tangible benefits to the park.Design/methodology/approach – The research is based on a case study approach within the organisation over a period of three months. The project team worked together with management and staff to deliver tangible benefits to the park. The team adopted a three stage approach linked by two decision points and used a variety of lean tools to help map the current state of practices in the park and to identify areas for improvement in the parks processes.Findings – The project succeeded in...

Survey: Allocation of quality control stations in multistage manufacturing systems

The allocation of quality control stations (AQCS) in multistage manufacturing systems has been studied extensively over the decades. This paper reviews the existing approaches, models comparison and solution techniques applied in AQCS. The relevance of the models and the effectiveness of the inspection strategies are examined by developing a generalised model. The conducting simulation experiments show that as the number of workstation increases the processing time to solve the problem increases significantly. This led to the development of a heuristic algorithm with local search. The performance the heuristic was compared with the optimization method based on complete enumeration method (CEM). It was found that the heuristic method can derive an acceptable solution significantly faster than the CEM. The review has shown that the most common techniques used are dynamic programming and non-linear programming. The paper suggests some biologically inspired optimisation algorithms can be of interest for further study.

A novel framework to link Prognostics and Health Management and Product-Service Systems using online simulation

Product-Service Systems (PSS) and Prognostics and Health Management (PHM) have so far been researched individually in different domains and as unrelated research theme. However, to guarantee the availability of the asset, which is a typical demand in some PSS contracts, it is fundamental for PSS providers to be able to properly manage the assets lifetime variability in order to avoid unscheduled downtimes and contract penalties. This paper describes part of a research project to investigate how PHM can support more effective fulfilment of some PSS contracts. In particular, this paper aims to present a novel framework to link PHM and PSS using online simulation. The paper also presents a prototype of the online simulation model and three experimental cases comparing the outcomes of the online simulation model against those obtained from the traditional simulation model.

Integrated strategic supply chain positioning for SMEs: an empirical study

Purpose – The purpose of this paper is to report on an investigation into the selection and evaluation of a suitable strategic positioning methodology for SMEs in Singapore. Design/methodology/approach – The research methodology is based on critical review of the literature to identify the potentially most suitable strategic positioning methodology, evaluation and testing of the methodology within the context of SMEs in Singapore, and analysis to determine the strengths and weaknesses of the methodology and opportunities for further research. Findings – This paper illustrates a leading integrated strategic positioning decision making process, which has been found to be potentially suitable for SMEs in Singapore, and the process is then applied and evaluated in two industrial case studies. Results in the form of strengths, weaknesses and opportunities are evaluated and discussed in detail, and further research to improve the process has been identified. Practical implications – A practical and integrated strategic supply chain positioning methodology for SMEs to define their own competitive space, among other companies in the manufacturing supply chain, so as to maximize business competitiveness. Originality/value – This paper contributes to the knowledge of the strategic positioning decision process as well as identifies further research to adapt the process for SMEs in Singapore.

A decision support tool to facilitate the design of cellular manufacturing layouts

This paper presents a decision support tool that can be used by practitioners and industrialists to solve practical cell formation problems. The tool is based on a cell formation algorithm that employs a set of heuristic rules to obtain a quasi-optimal solution from both component routing information and other significant production data. The algorithm has been tested on a number of data sets obtained from the literature. The test results have demonstrated that in many cases the algorithm has produced an exceptional performance in terms of the grouping efficiency, grouping efficacy and quality index measures. The algorithm, to an extent, overcomes common problems in existing cell formation methods such as in dealing with ill-structured matrices and achieving rational cell sizes.

Supporting shop floor workers with a multimedia task-oriented information system

This paper reports the work carried out as part of an industrial research project sponsored by a major telecommunication industry based in the UK. The main aim of the research was to investigate the extent to which a multimedia-based information system, developed for shop floor workers, has contributed to the increased efficiency and productivity of manufacturing operations. To achieve this, the work has focused on the design and execution of the evaluation of the system. Due to the fact that the direct impact of the implementation of the information system developed was difficult to demonstrate, it was decided to adopt the system usage as a surrogate of the systems success and the user acceptance of the system was evaluated using both the Technology Acceptance Model and the Task-Technology Fit model.

Practical approach to experimentation in a simulation study

Simulation study of complex production facilities can be a challenging task for manufacturing engineers as it requires skills to build the models and to conduct experiments. Accurate modeling but inadequate experimentation may lead to poor decision and can be detrimental particularly when financial investment is involved. This paper proposes a practical approach to simulation experimentation in the context of simulation study of an engine assembly line. The overall aim of the study was to increase the productivity and efficiency of the line. The approach was deployed in the form of a methodology that was used to select the most feasible outcome from a series of simulation experiments, taking into account the minimum effort/investment needed to implement the improvement.

Applying performance measures to support decision-making in supply chain operations: a case of beverage industry

Performance measurement systems (PMS) have commonly been applied to evaluate and reward performances at managerial levels, especially in the context of supply chain management. However, evidence suggests that the effective use of PMS can also positively influence the behaviour and improve performance at an operational level. The motivation is to accomplish organisational goals, namely to increase supply chain flexibility by responding to evermore-varying customer demands in a timely manner. The purpose of the study described in this paper was to develop a conceptual framework that adopts performance measures for ex-ante decision-making at an operational level within the supply chain. To guide the research, five questions were asked and subsequently key gaps have been identified. In an attempt to fill the gaps, a case study at a major global brand beverage company has been carried out, and as a result, a conceptual framework of the PMS has been developed. Overall, the research offers a foundation of the applicability and impact of PMS in the supply chain and provides a framework that attends to some of the potential uses of PMS that so far have not been practically applied. The outcomes from the testing indicate that the initial gaps identified in the literature have been addressed and that the framework is judicious with scope for practical applicability. The framework is deemed worthy of further testing in different operational contexts of the supply chain.