Herman Steyn

Project management applications of the theory of constraints beyond critical chain scheduling

Abstract The application of the Theory of Constraints (TOC) is an approach that can be used to develop a variety of management techniques. As a result of the multi-disciplinary nature of project management a variety of different applications within project management are possible. The application of the TOC approach to project scheduling led to the development of the “critical chain” technique that has been the subject of discussions in literature. This paper explains why TOC was initially applied only to project scheduling. A second application of TOC is to manage resources shared by a number of concurrent projects. The basic principles of this second application are discussed in this paper. In addition to the above-mentioned two applications the TOC approach can also be applied to other areas of project management such as project cost management and project risk management.

An investigation into the fundamentals of critical chain project scheduling

Abstract The theory of constraints (TOC) is a philosophy that is used to develop specific management techniques. The TOC technique for project time management is often referred to as the “critical chain” technique. There are indications that this technique is increasingly being used. This paper reviews the literature on this application of TOC. It also investigates the assumptions and principles underlying the approach. The technique is considered an innovation that would be useful to organisations capable of accepting a new paradigm.

Determining the most important factors for sustainable energy technology selection in Africa: Application of the focus group technique

The supply of sustainable energy is a crucial factor for development in Africa. This is important both for business development and for the supply of energy to households in order to save time and thus enable members of households to be economically active. Without sustainable energy, poverty reduction and economic development in Africa are not achievable. Africa has limited skilled human resources and thus the selection of successful, integrated technological systems is imperative. This study focuses on the identification of factors to be taken into account when identifying the most sustainable technological systems for Africa. Focus groups, using the nominal group technique, can be used successfully in problem definition and first order identification. The purpose of this focus group was to identify the first order factors for the study, which were then used to inform the Delphi study that followed. A pre-existing group of specialists in the energy field was used. During this process, thirty eight factors deemed to be important were identified. The factors were categorized into six clusters, namely: technology factors, social factors, institutional or regulatory factors, site selection factors, economical or financial factors, and achievability by the specific organisation.

BUFFER SIZING FOR THE CRITICAL CHAIN PROJECT MANAGEMENT METHOD

Methods for sizing project and feeding buffers for critical chain project management are investigated. Experiments indicate that – in the absence of bias, and for certain classes of bias – buffer consumption is independent of the mean duration of a chain. Generally the popular method – a buffer size equal to 50% of the longest path leading to it – gives rise to excessively large buffers. Buffers sized according to the square root of the sum of squares perform well in the absence of bias, but with bias present the performance is unacceptably poor. A new approach to buffer sizing is proposed. OPSOMMING Metodes vir groottebepaling van projek- en saamvloeibuffers vir kritieke-ketting projekbestuur word ondersoek. Eksperimente dui daarop dat – in die afwesigheid van onewewigtigheid, en vir sekere tipes onewewigtigheid – bufferverbruik onafhanklik is van die gemiddelde lengte van ’n ketting. Oor die algemeen veroorsaak die metode van buffergrootte – gelyk aan 50% van die langste pad wat tot die buffer lei – onnodige groot buffers. Buffers bepaal met die metode van die vierkantswortel van die som van kwadrate, vaar goed in die afwesigheid van onewewigtigheid, maar vaar onaanvaarbaar swak wanneer onewewigtigheid teenwoordig is. ’n Nuwe metode vir die bepaling van buffergrootte word voorgestel.

DETERMINING THE MOST IMPORTANT FACTORS FOR SUSTAINABLE ENERGY TECHNOLOGY SELECTION IN AFRICA

The supply of sustainable energy is a crucial factor for development in Africa. This is important both for business development and for the supply of energy to households in order to save time and thus enable members of households to be economically active. Without sustainable energy, poverty reduction and economic development in Africa are not achievable. Africa has limited skilled human resources and thus the selection of successful, integrated technological systems is imperative. This study focuses on the identification of factors to be taken into account when identifying the most sustainable technological systems for Africa. Focus groups, using the nominal group technique, can be used successfully in problem definition and first order identification. The purpose of this focus group was to identify the first order factors for the study, which were then used to inform the Delphi study that followed. A pre-existing group of specialists in the energy field was used. During this process, thirty eight factors deemed to be important were identified. The factors were categorized into six clusters, namely: technology factors, social factors, institutional or regulatory factors, site selection factors, economical or financial factors, and achievability by the specific organisation.

AN EXPLORATORY ASSESSMENT OF PROJECT DURATION IN MULTIPLE-PROJECT SCHEDULES WHERE RESOURCES ARE ALLOCATED BY THE THEORY OF CONSTRAINTS METHOD

The theory of constraints (TOC) method for managing multiple projects provides a relatively new and simple heuristic for allocating constrained resources to projects. While this method is increasingly being used, there is little information about its merit and it has not yet been subjected to extensive testing. In this paper literature relevant to the allocation of resources to multiple projects is first reviewed. Thereafter the TOC method for allocating resources to multiple projects is explained. Finally the paper reports on an exploratory study to evaluate the effect that the TOC method for assigning resources has on project duration. OPSOMMING Die “Theory of Constraints” (TOC)-metode vir die bestuur van veelvuldige projekte bied ’n relatief nuwe en eenvoudige heuristiek om beperkte hulpbronne aan projekte toe te ken. In die praktyk raak hierdie metode toenemend gewild maar daar is weinig inligting beskikbaar oor die meriete daarvan. Die metode is ook nog nie aan uitgebreide toetsing onderwerp nie. In hierdie artikel word ’n oorsig gegee oor die literatuur van hulpbrontoedeling. Tweedens word die TOC metode vir hulpbrontoedeling bespreek. Daarna word verslag gedoen oor ’n eksploratiewe ondersoek na die effek wat die TOC metode op die tydsduur van projekte het.

DEFINING 'PROJECT SUCCESS' FOR A COMPLEX PROJECT - THE CASE OF A NUCLEAR ENGINEERING DEVELOPMENT

The case of a nuclear engineering project was investigated to establish the relevant success criteria for the development of complex, high-technology systems. The project was first categorised according to an existing scheme, and the Delphi method was used to determine the criteria for project success that apply to this specific case. A framework of project success dimensions was extended to include criteria that are of specific importance for the project under consideration. While project efficiency (delivery on time and within budget) obviously still needs to be controlled, the results provide empirical evidence for the notion that, for ‘super high tech’ projects, this is relatively less important. The relative importance of the dimensions of success was also evaluated and presented on a timeline stretching from project execution to 10 years after project completion. This provided empirical evidence for certain concepts in the literature.

PROJECT MANAGEMENT MATURITY: AN ASSESSMENT OF MATURITY FOR DEVELOPING PILOT PLANTS

Despite the current economic climate, the South African mining and engineering industry is experiencing a very promising future, with a large number of capital projects in the offing. It is inevitable that pilot plant development will form part of this future as a risk mitigation technique. This study found that, even though the terms ‘pilot plant’ and ‘project management maturity’ are familiar within the industry, no link between these two could be found in the literature. A number of maturity models exist; and one developed by PMSolutions was selected to perform an assessment of the current level of project management maturity within the South African mining and engineering industry pertaining to the development of pilot plants. The Delphi technique was used to determine the views of experts in the South African mining, mineral processing, petrochemical, nuclear, and mechanical sectors regarding this maturity. A significant difference was observed between the current level of maturity and the required level of maturity in all but one of the nine knowledge areas defined by the Project Management Institute. The two knowledge areas of project time and risk management showed significant differences between current and required maturity levels, and were identified as key areas for improvement. OPSOMMING Ten spyte van die huidige ekonomiese klimaat ondervind die Suid-Afrikaanse mynbou- en ingenieursbedryf ’n baie bemoedigende toekoms, met ’n groot aantal kapitaalprojekte in die vooruitsig. Ten einde risiko’s te verlaag, sal die ontwikkeling van loodsaanlegte noodwendig deel van hierdie toekoms uitmaak. Daar is gevind dat, alhoewel die terme ‘loodsaanleg’ en ‘projekbestuur volwassenheid’ in die nywerheid bekend is, geen skakeling van hierdie twee terme in die literatuur opgespoor kon word nie. ’n Aantal volwassenheid modelle bestaan; en een wat deur PMSolutions ontwikkel is, is gekies om die huidige vlak van projekbestuur volwassenheid in die Suid-Afrikaanse mynbou- en ingenieursbedryf ten opsigte van loodsaanlegte te bepaal. Die Delphi tegniek is gebruik om die sienings van deskundiges in die Suid-Afrikaanse mynbou-, mineraalprosessering-, petrochemiese-, kern-, en meganiese sektore oor die genoemde volwassenheid te bepaal. ’n Beduidende verskil is waargeneem tussen die huidige en die gewensde vlakke van volwassenheid in agt van die nege kennisareas soos gedefinieer deur die Amerikaanse Project Management Institute. Beduidende verskille tussen huidige en gewensde vlakke van volwassenheid is veral in die twee kennisareas projek tydbestuur en projek risikobestuur gevind, en dui op areas vir verbetering.

A CONCEPTUAL MODEL FOR IMPROVED PROJECT SELECTION AND PRIORITISATION

Project portfolio management processes are often designed and operated as a series of stages (or project phases) and gates. However, the flow of such a process is often slow, characterised by queues waiting for a gate decision and by repeated work from previous stages waiting for additional information or for re-processing. In this paper the authors propose a conceptual model that applies supply chain and constraint management principles to the project portfolio management process. An advantage of the proposed model is that it provides the ability to select and prioritise projects without undue changes to project schedules. This should result in faster flow through the system. OPSOMMING Prosesse om portefeuljes van projekte te bestuur word normaalweg ontwerp en bedryf as ’n reeks fases en hekke. Die vloei deur so ’n proses is dikwels stadig en word gekenmerk deur toue wat wag vir besluite by die hekke en ook deur herwerk van vorige fases wat wag vir verdere inligting of vir herprosessering. In hierdie artikel word ‘n konseptuele model voorgestel. Die model berus op die beginsels van voorsieningskettings sowel as van beperkingsbestuur, en bied die voordeel dat projekte geselekteer en geprioritiseer kan word sonder onnodige veranderinge aan projekskedules. Dit behoort te lei tot versnelde vloei deur die stelsel.

COMPARISONS BETWEEN AND COMBINATIONS OF DIFFERENT APPROACHES TO ACCELERATE ENGINEERING PROJECTS

In this article, traditional project management methods such as PERT and CPM, as well as fast-tracking and systems approaches, viz. concurrent engineering and critical chain, are reviewed with specific reference to their contribution to reducing the duration of the execution phase of engineering projects. Each of these techniques has some role to play in the acceleration of project execution. Combinations of approaches are evaluated by considering the potential of sets consisting of two different approaches each. While PERT and CPM approaches have been combined for many years in a technique called PERT/CPM, new combinations of approaches are discussed. Certain assumptions inherent to PERT and often wrong are not made by the critical chain approach. OPSOMMING In hierdie artikel word tradisionele projekbestuurbenaderings soos PERT en CPM asook projekversnelling en stelselbenaderings, naamlik gelyktydige ingenieurswese, en kritiekeketting-ondersoek met betrekking tot die bydrae wat elk tot die versnelling van die uitvoeringsfase van ingenieursprojekte kan lewer. Elk van hierdie benaderings kan ‘n spesifieke bydrae tot die versnelling van projekte lewer. Kombinasies, elk bestaande uit twee verskillende benaderings, word geevalueer. Terwyl PERT en CPM reeds baie jare lank in kombinasie gebruik word, word nuwe kombinasies ook hier bespreek. Sekere aannames inherent aan die PERT-benadering is dikwels foutief. Hierdie aannames word nie deur die kritieke-ketting-benadering gemaak nie.