Theopisti C. Papadopoulou

Leanness: experiences from the journey to date

Purpose – Although leanness is certainly not a new concept it is doubtless still relevant. Interestingly, newly developed manufacturing paradigms and systems are always examined in relation to leanness. In other words, leanness serves in most cases as the landmark paradigm with which comparisons are being drawn between the latter and recently pioneered approaches. The purpose of this paper is to highlight the evolutional orbit that leanness has followed over the years and serve as a herald of the current state of this evolution, which will be discussed further, in a separate paper.Design/methodology/approach – A great part of this paper is devoted to highlighting the misconceptions surrounding issues such as what leanness really constitutes and what are the key concepts and practices that leanness encompasses. Two successful lean transition stories are presented showing how these lean tools and techniques were implemented in the cases of two UK‐based manufacturing companies.Findings – Because of its inher...

Systems dynamics modelling of a manufacturing supply chain system

Abstract Supply chains are multifaceted structures focusing on the integration of all the factors involved in the overall process of production and distribution of end products to the customers. Growing interest in supply chain systems has highlighted the need to adopt appropriate approaches that can ensure the efficient management of their complexity, enormity and broadness of scope. With the main aim of supply chain management being to optimise the performance of supply chains, attention is mainly drawn to the development of modelling frameworks that can be utilised to analyse and comprehend the dynamic behaviour of supply chains. While there have been only a few supply chain modelling attempts reported in the literature, this paper proposes a modelling framework that is used to simulate the operation of a supply chain network of moderate complexity. The proposed model comprises four echelons and is build around a central medium-sized manufacturing company operating as a typical Make-to-Order (MTO) system. The developed model was built using a systems dynamics (SD) approach. The operations performed within a supply chain are a function of a great number of key variables which often seem to have strong interrelationships. The ability of understanding the network as a whole, analysing the interactions between the various components of the integrated system and eventually supplying feedback without de-composing it make systems dynamics an ideal methodology for modelling supply chain networks. The objective of the paper is to model the operation of the supply chain network under study and obtain a true reflection of its behaviour. The modelling framework is also used to study the performance of the system under the initial conditions considered and compare it with that obtained by running the system under eight different scenarios concerning commonly addressed real-life operational conditions. The modelling effort has focused on measuring the supply chain system performance in terms of key metrics such as inventory, WIP levels, backlogged orders and customer satisfaction at all four echelons. The study concludes with the analysis of the obtained results and the conclusions drawn from contrasting the system’s performance under each investigated scenario to that of the benchmark model.

Causes of cost overruns in transport infrastructure projects in Asia: their significance and relationship with project size

Purpose – One of the worlds largest construction markets is in Asia where construction activity is boosted by investment on transport infrastructure. This paper aims to identify and analyse causes of cost overruns in transport infrastructure projects in Asia and assess their importance and statistical relationship with project size.Design/methodology/approach – The paper pursues the following objectives. First, it identifies factors contributing to cost overruns. Second, using case data and regression analysis, it establishes the statistical relationship between project size and cost overruns. Third, it analyses questionnaire data to rank causes of cost overruns according to their frequency, severity and significance. Last, the paper identifies contract types mostly associated with cost escalation.Findings – The findings confirm a moderate correlation between cost overruns and one indicator of project size. Awarding contracts to the lowest bidder is identified as the most significant cause of cost overru...

Simulation of JIT performance in a printing shop

A medium sized UK based academic publisher own a subsidiary printing business. Presently, Academic Printers (AP) is experiencing production line flow problems reducing the efficiency of the operation. Most of the problems are generated by the imbalanced workflow through the system. By implementing a JIT production planning system it is hoped that some of the production problems can be resolved. Using the simulation software a model was created to investigate the performance of the AP under a variety of operating conditions. Results showed that operating the system with JIT control would not produce economic performance improvements due to constraints applied by the printing process.