FORRIDGE - Principles of good practice in material flow

The post World War II Industrial Revolution has driven production away from the old 'economies of scale' to the new 'economies of scope'. Apparently Japanese led, the associated roots of present good practice on material flow can be traced back in the USA to Jay Forrester and in the UK to Jack Burbidge. Specifically, in the supply chain scenario, Forrester exposed the importance of system structure in relating and integrating information flow with material flow. Similarly Burbidge led the way in exploiting cycle time reduction, synchronization of orders throughout the chain, simplified product structures, and streamlined component flows. This paper unites their contributions to material flow engineering and shows how present day system design methodologies incorporate their ideas on best practice. These principles are particularly relevant to the product delivery process (PDP) which governs material flow in supply chains.     

Enabling the seamless supply chain by exploiting the four smooth material flow controls

A decade after the publication of the concept of smooth material flow via four fundamental principles related to the work of Jay Forrester and John Burbidge (FORRIDGE) the influence of this work on academe and industry is discussed. We show that by extension of their principles via a three-level model which includes the vision and the toolkit, substantial contributions have been made towards new management theory. The associated 12 simplicity rules and uncertainly circle concepts have been exploited within the structured framework provided by the quick scan audit methodology. This generates value stream classification ranging from baseline to exemplar, and a design procedure aimed at material flow best practice. A detailed case study demonstrates the improved industrial performance achievable by this means.     

Causes,effects and mitigation of unreliable healthcare supplies

This study investigates the means by which hospitals can improve the reliability of their medical supply value streams. Field research involving pharmacy supplies in eight Australasian public sector hospitals utilised a rigorous, multi-method data collection procedure based around the uncertainty circle model. Value stream maturity, performance inhibitors and pathways to effective improvement are explored. The high levels of value stream uncertainty detected are commonly the result of process immaturity and poor inter-functional integration. Chief among the common root causes is failure by the executive to acknowledge the strategic value of medical supplies management, which ultimately leads to higher materials cost and increased risk of a medical mishap. The study demonstrates how managers can use systems thinking and a context-free performance benchmark to identify effective interventions and potentially transferable best practices.     

Productivity drift in extended learning curves

The pattern of changes in the Extended Learning Curves representing the performance of 114 assembly workers in an electronics firm is examined in terms of changes in productivity drift over long periods of time. It is shown that 2 types of discontinuities can occur. The first consists of a temporary levelling off in productivity followed by a recovery to new higher levels of productivity; the second has a sustained period of negative productivity drift. A number of work facets are statistically tested as possible causes of these patterns of productivity drift, but, the only significant relationship (at P ≤ 0.05 level) is with length of service in job. Some evidence is presented to show that conventional work measurement methods are not effective in terms of assessing the true work output of experienced workers since such workers are able to beat the system by claiming those allowances which are most difficult to cross-check.     

On the versatility of Little’s Law in operations management: a review and classification using vignettes

Abstract

Despite Little’s Law being considered as one of the ‘laws’ of operations management, evidence of its application in an empirical context is diverse and diffuse. Hence, this paper aims to identify, classify and consolidate published empirical applications of Little’s Law in a systematic manner to better understand its versatility. This paper undertakes a systematic literature review of the databases of the five main publishers of operations management journals and snowball sampling for additional papers. A final sample of 128 empirical journal articles is identified and categorized. Tactical, medium-term decisions relating to capacity dynamics and operations re-engineering are the most popular categories. To give further insights into versatility, vignettes for each category are developed. The review and vignettes confirm Little’s Law as a highly relevant paradigm to operations management decisions due to its empirical versatility across levels, sectors and time domains. The paper suggests four factors to underline the empirical versatility of Little’s Law in operations management: applicability, utility, simplicity and visibility.     

A production engineering approach to robot selection

The successful introduction of robots into an industrial enterprise means real commitment, engineering support, and detailed involvement in the planning of an integrated manufacturing system. In particular, the production engineer is clearly seen in this context to be the system designer. He must therefore be in a position to specify the performance of all man and machine components within the system such that productivity is maximised. Robot types are reviewed, and analogies between man and machine are used to introduce the RTM concept. Finally, a simple method is given for estimating robot throughput times from elementary velocity profiles. The fall-off in throughput due to the effect of many small robot movements is emphasised.