This dissertation develops a process improvement method for service operations based on the Theory of Constraints (TOC), a management philosophy that has been shown to be effective in manufacturing for decreasing WIP and improving throughput. While TOC has enjoyed much attention and success in the manufacturing arena, its application to services in general has been limited. The contribution to industry and knowledge is a method for improving global performance measures based on TOC principles. The method proposed in this dissertation will be tested using discrete event simulation based on the scenario of the service factory of airline turnaround operations. To evaluate the method, a simulation model of aircraft turn operations of a U.S. based carrier was made and validated using actual data from airline operations. The model was then adjusted to reflect an application of the Theory of Constraints for determining how to deploy the scarce resource of ramp workers. The results indicate that, given slight modifications to TOC terminology and the development of a method for constraint identification, the Theory of Constraints can be applied with success to services. Bottlenecks in services must be defined as those processes for which the process rates and amount of work remaining are such that completing the process will not be possible without an increase in the process rate. The bottleneck ratio is used to determine to what degree a process is a constraint. Simulation results also suggest that redefining performance measures to reflect a global business perspective of reducing costs related to specific flights versus the operational local optimum approach of turning all aircraft quickly results in significant savings to the company. Savings to the annual operating costs of the airline were simulated to equal 30% of possible current expenses for misconnecting passengers with a modest increase in utilization of the workers through a more efficient heuristic of deploying them to the highest priority tasks. This dissertation contributes to the literature on service operations by describing a dynamic, adaptive dispatch approach to manage service factory operations similar to airline turnaround operations using the management philosophy of the Theory of Constraints.

This study used action research to study the implementation of Critical Chain methodology in a multi-project environment. It used a medium sized company, which is an original equipment manufacturer, but due to the complexity of the equipment each is executed as a project. This creates a multi-project environment.The object of the research was to find the contributing and inhibiting factors to CC implementation. It further sought to discover improvements in business performance due to CC methodology.The study found resistance to change prevented CC implementation. The resistance to change was supported by incorrect application of CC principles and a false sense that CC is contributing to the business. On business performance improvements it was found that order intake improvements of thirty seven per cent year on year and reduction in lead time of projects due to implementation of CC principles. The latter also opened new markets which strategically benefitted the company. / Dissertation (MBA)--University of Pretoria, 2012. / Gordon Institute of Business Science (GIBS) / unrestricted

The objective of this thesis is to demonstrate the use of the Activity-Based Costing (ABC) approach together with the Theory of Constraints (TOC) philosophy in determining the optimal product-mix and restrictive bottlenecks of a company. The contribution of this thesis is a new product-mix decision model that uses activity-based cost information. This new model is proposed to be used with the TOC philosophy in order to improve the financial performance of a company.</p> Four case studies, all of which are based on hypothetical data, are prepared in this research to show the applicability of the proposed model in different manufacturing environments. Specifically, the first case study shows that the conventional product-mix decision model and the model developed in this thesis can give significantly different results regarding the best product-mix and associated bottlenecks of a company. The second case study demonstrates the use of the proposed product-mix decision model in a complex manufacturing environment. Specifically, this case study shows how companies should consider alternatives such as activity flexibility and outsourcing to improve their profitability figures. The third case study is an extension of the second case study, and it is prepared to illustrate that the proposed model can be extended to include more than one time period. The final case study demonstrates the applicability of the proposed model in a lean manufacturing environment.</p> Using the proposed model developed in this research will give managers more accurate information regarding the optimum product-mix and critical bottlenecks of their companies. By applying the TOC philosophy based on this information, managers will be able to take the right actions that will improve the profitability of their companies. Specifically, they will be able to observe the effects of several alternatives, such as activity flexibility and outsourcing, on the throughput of the whole system. In addition, the proposed model should help managers to prevent making decisions that sub-optimize the system. This may occur, for example, when using only the most efficient methods to produce each product even though the capacities of these methods are limited and some other less efficient methods are currently available in the company. By extending the model to include more than one time period, managers will be able to estimate the potential bottlenecks and the amount of idle capacities of each non-bottleneck activity performed in the company ahead of time. This information is powerful and can give companies a substantial advantage over their competitors because the users of the new model will have enough time to improve the performance of their potential bottlenecks and to search for more profitable usage of excess capacities before the actual production takes place. / Master of Science

No description available.

Konkurrensen i tillverkningsföretag ökar ständigt och detta medför att det ställs hårda krav på produktkvalitet och förmågan att leverera produkter i tid. För att företag ska kunna nå upp till dessa mål krävs utveckling och ständiga förbättringar i takt med den växande marknaden. Detta uppnås på olika sätt men ett vanligt sätt är att arbeta med förbättringsmetodiker. Val av förbättringsmetodik beror på företagets tillverkning, kunskap inom företaget och resurser inom företaget. Att välja förbättringsmetodik anpassat till den egna organisationen är väldigt svårt för många organisationer och många organisationer ställer sig frågan: ”Vilken metod passar bäst för den egna organisationen?”. Målet med examensarbetet är att undersöka om och hur Lean Production och Theory of Constraints kan användas i företag med high-mix low-volume produktion. Med hjälp av en litteraturstudie och en fallstudie har följande frågor besvarats: 1) hur Lean Prodution och Theory of Constraints används i en HMLV produktion och hur dessa kombineras, 2) hur produktionsflödet styrs enligt Lean Production och Theory of Constraints för att effektivisera en produktionsprocess i ett HMLV företag, 3) vilka personliga paradigm och policys det uppstår enligt Lean Production och Theory of Constraints i HMLV företag och vad sambandet mellan dessa och kvalitet är. Resultat från litteraturstudien och fallstudien visar att Lean Production och dess verktyg går bra att använda kombinerat med Theory of Constraints i HMLV företag med vissa undantag. Dessa undantag är dock inga undantag som säger att Lean Production och dess verktyg inte går att använda i HMLV företag i kombination med Theory of Constraints. Dessa undantag behöver endast anpassas för HMLV produktion. Resultaten visade också att standardiserat arbete i en produktion har en avgörande roll när Lean Production och Theory of Constraints används. Standardiserat arbete bidrar till att fortsatt utveckling och implementering underlättas. Resultaten visar även på att produktionsflödet kan anpassas med hjälp av metoder inom Lean Production och Theory of Constraints och att detta göras bäst när dessa två metodiker kombineras. Vidare visade resultaten att nya investeringar i form av ny utrustning inte är nödvändiga i många fall. Detta förutsätter att flaskhalsar, så som personliga paradigm och policys, identifieras. Resultaten visade även att kvaliteten är direkt kopplad till dessa två flaskhalsar och att en investering i ledarskap är att föredra. / Competition between manufacturing companies is constantly increasing and this causes high demands on product quality and ability to deliver products in time. For companies to be able to reach these goals it is necessary to work with development and continuous improvements and respond to the current pace of the market. This can be achieved in different ways, but a common method is to work with improvement methodologies. Selecting which improvement methodologies to use depends on a company’s manufacturing, knowledge, and resources. Many organisations find it difficult to choose improvement methodologies for their particular organisation and ask the question: “Which method is best suited for our organisation?”. The goal of this study is to examine whether and how Lean Production and Theory of Constraints can be utilized in companies with high-mix low-volume production. By performing a literature review and a case study the following questions have been answered: 1) how Lean production and Theory of constraints are utilized in a HMLV production system and how they can be combined, 2) how the production flow is controlled according to Lean Production and Theory of Constraints to improve the efficiency of a production process in a HMLV company, 3) what personal paradigms and policys arise according to Lean Production and Theory of Constraints in HMLV company and what the relationship between these and quality is. Results from the literature review and case study show that Lean Production and its tools are possible to use in a combination with Theory of Constraints in HMLV companies with some exceptions. However there is no exceptions saying that Lean Production and its tools combined with Theory of Constraints can not be utilized in HMLV companies. These exceptions only need to be adjusted for HMLV production. The results also showed that standardized work in a production process plays a crucial role when combining Lean production with Theory of Constraints. Standardized work contributes to facilitation of further development and implementation. The results show that the production flow can be adjusted using methods from Lean Production and Theory of Constraints, and that this is done best by combining these two methodologies. Furthermore, the results showed that in many cases new investments in the form of new equipment are not necessary. This assumes that bottlenecks, such as personal paradigms and policies are identified. The results showed that quality is directly linked to these two bottlenecks and that an investment in management is preferable.

Three methodologies are associated with production optimisation, namely, Theory of Constraints (TOC), Lean and Six Sigma – and each boasts with a number of success stories. This dissertation addresses the possibility of implementing all three these methodologies in a specific sequence at an organisation and also sets out to determine the impact of this implementation. A literature survey was conducted on all three stand-alone methodologies as well as on the combined methodology, which is called the Theory of Constrains Lean Six Sigma (TLS). TLS literature suggests that TOC should be implemented first with a view to identify the constraint in an organisation. Lean implementation should follow in order to eliminate any waste in the organisation. Lastly, Six Sigma should be implemented to optimise the process variability. TOC literature explains that The Goal of any organisation is to make money. All other objectives are only the means of achieving The Goal. The literature further indicates that the constraint in any organisation determines the drumbeat, and that this constraint should be managed by means of the Drum-Buffer-Rope methodology. Lean literature points towards 14 Management Principles by means of which an organisation should be managed in order to become a Lean organisation, while Six Sigma literature is concerned with the DMAIC (Define-Measure-Analyse-Improve-Control) methodology used for improvement projects and the belt system that is used to manage these improvement projects. Jonker Sailplanes, a sailplanes manufacturer in Potchefstroom, South Africa, was used as a case study for the implementation of TLS. A description is given of the processes and procedures that were followed before and after the implementation of TLS. The TLS methodology had to be adapted in order to meet the specific needs of Jonker Sailplanes into an adapted 14-step TLS implementation plan. After implementing TOC and Lean at Jonker Sailplanes, it was found that the organisation was not ready for the transition from Lean projects to Six Sigma projects. The implementation of Six Sigma was therefore referred for future research. One of the most significant findings of the current study was the very positive impact that the implementation of TLS had on the organisation: the production tempo (throughput) of the organisation has increased while the operating expenses per aircraft have decreased. This confirms that the profit per aircraft has increased. A critical evaluation of the implementation of the TLS methodology can therefore maintain that the implementation of TLS at Jonker Sailplanes was a success since the production tempo (throughput) and the organisational profit were increased and the implementation of the methodology was done with relative ease. In terms of interpreting results it was also necessary to set out how Jonker Sailplanes proceeded from a prototyping environment to a production setup, and how specifically identifying the constraint helped to achieve this transition. Furthermore, is it argued that when Lean is implemented before TOC, this could move the organisation away from The Goal, which is to make money. The interpretation of findings suggests that the procedure followed at Jonker Sailplanes was the most appropriate one. Finally, recommendations are made for future studies in terms of how to further improve the impact of the TLS implementation at Jonker Sailplanes. / Thesis (M.Ing. (Development and Management))--North-West University, Potchefstroom Campus, 2011.

Three methodologies are associated with production optimisation, namely, Theory of Constraints (TOC), Lean and Six Sigma – and each boasts with a number of success stories. This dissertation addresses the possibility of implementing all three these methodologies in a specific sequence at an organisation and also sets out to determine the impact of this implementation. A literature survey was conducted on all three stand-alone methodologies as well as on the combined methodology, which is called the Theory of Constrains Lean Six Sigma (TLS). TLS literature suggests that TOC should be implemented first with a view to identify the constraint in an organisation. Lean implementation should follow in order to eliminate any waste in the organisation. Lastly, Six Sigma should be implemented to optimise the process variability. TOC literature explains that The Goal of any organisation is to make money. All other objectives are only the means of achieving The Goal. The literature further indicates that the constraint in any organisation determines the drumbeat, and that this constraint should be managed by means of the Drum-Buffer-Rope methodology. Lean literature points towards 14 Management Principles by means of which an organisation should be managed in order to become a Lean organisation, while Six Sigma literature is concerned with the DMAIC (Define-Measure-Analyse-Improve-Control) methodology used for improvement projects and the belt system that is used to manage these improvement projects. Jonker Sailplanes, a sailplanes manufacturer in Potchefstroom, South Africa, was used as a case study for the implementation of TLS. A description is given of the processes and procedures that were followed before and after the implementation of TLS. The TLS methodology had to be adapted in order to meet the specific needs of Jonker Sailplanes into an adapted 14-step TLS implementation plan. After implementing TOC and Lean at Jonker Sailplanes, it was found that the organisation was not ready for the transition from Lean projects to Six Sigma projects. The implementation of Six Sigma was therefore referred for future research. One of the most significant findings of the current study was the very positive impact that the implementation of TLS had on the organisation: the production tempo (throughput) of the organisation has increased while the operating expenses per aircraft have decreased. This confirms that the profit per aircraft has increased. A critical evaluation of the implementation of the TLS methodology can therefore maintain that the implementation of TLS at Jonker Sailplanes was a success since the production tempo (throughput) and the organisational profit were increased and the implementation of the methodology was done with relative ease. In terms of interpreting results it was also necessary to set out how Jonker Sailplanes proceeded from a prototyping environment to a production setup, and how specifically identifying the constraint helped to achieve this transition. Furthermore, is it argued that when Lean is implemented before TOC, this could move the organisation away from The Goal, which is to make money. The interpretation of findings suggests that the procedure followed at Jonker Sailplanes was the most appropriate one. Finally, recommendations are made for future studies in terms of how to further improve the impact of the TLS implementation at Jonker Sailplanes. / Thesis (M.Ing. (Development and Management))--North-West University, Potchefstroom Campus, 2011.

Os Métodos Ágeis surgiram no final da década de 90, como uma alternativa aos métodos prescritivos de desenvolvimento de software. Eles propõem uma nova abordagem de desenvolvimento, eliminando gastos com documentação excessiva e burocrática, enfatizando a interação entre as pessoas e as atividades que efetivamente trazem valor ao cliente. Nos últimos anos, diversos princípios e práticas baseados na indústria de manufatura foram incorporadas pelos Métodos Ágeis de desenvolvimento de software. Um dos princípios absorvidos é o de melhorar a eficácia de uma organização através de melhorias globais. Embora este princípio seja bem difundido nos Métodos Ágeis, utilizá-lo não é uma tarefa fácil. Nem sempre é fácil ter uma visão global do processo de desenvolvimento. Além disso, para realizar melhorias globais é necessário descobrir a causa para possíveis problemas, o que também pode ser uma tarefa difícil. Esse trabalho investiga duas abordagens da indústria de manufatura que enxergam uma organização como um sistema no qual todas as partes são inter-relacionadas. Com base nelas, três abordagens de desenvolvimento de software existentes são analisadas. Finalmente, um estudo comparativo foi feito para avaliar as principais características dos métodos de desenvolvimento estudados. Esse estudo estende o trabalho feito por Abrahamssom et al., no livro Agile Software Development: Current Research and Future Directions, avaliando o desempenho dos métodos seguindo o arcabouço proposto pelos mesmos autores. / Agile methods appeared in the late 90\'s as an alternative approach to the classic prescriptive planning approaches to software development. They propose a new style of development, eliminating excessive and bureaucratic documentation, and emphasizing the interactions between people collaborating to achieve high productivity and deliver high-quality software. In the last few years, several principles and practices based on the manufacturing industry were incorporated by Agile software development. One of the principles absorbed is to improve the effectiveness of an organization through an overall improvement. Although this principle is quite widespread in Agile Methods, using it is not an easy task. It is not easy to get the big picture of the development process. Moreover, to achieve overall improvements is necessary to discover the cause of possible problems, which can also be a difficult task. This work investigates two approaches in the manufacturing industry that shares the assumption that the whole organization is focused on overall throughput, not on micro-optimization. Based on then, three approaches to existing software development are analyzed. Finally, a comparative study was done to assess the main characteristics of the studied methods. This study extends the work done by Abrahamssom et al. In the book Agile Software Development: Current Research and Future Directions, evaluating the performance of the methods following the framework proposed by the same authors.

Apribojimų teorijos principus Lietuvoje pastarąjį dešimtmetį savo veikloje, padedant profesionaliems konsultantams, ėmė naudoti vos keli procentai įmonių, tačiau apribojimų teorijos principų panaudojimas paslaugų įmonėse nėra išsamiai ištirtas. Šiuo magistro baigiamuoju darbu siekiama atskleisti analizuojamos teorijos poveikį konkrečiai Lietuvoje veikiančiai paslaugų įmonei.Tyrimas patvirtino hipotezę, kad aprobojimų teorijos metodus galima sėkmingai taikyti pasaugų versle, jie padeda surasti geriausius problemų sprendimo būdus, tačiau kiekviena organizacija yra gyvas organizmas, išsprendus vienas problemas atsiranda kitos. / Despite the fact that in the last decade just small percentage of companies in Lithuania with help from professional consultants, applied the Theory of Constraints principles in their business activities, still the issue of applying the Theory of Constraints principles in services providing companies is not thoroughly explored. This Master’s thesis aims to reveal the impact of the analyzed theory on the particular services providing company.The hypothesis was confirmed by the research that the Theory of Constraints methods could be successfully applied to service business, they are used to find the best solutions to the problems, but each organization is like a live organism which confronts new problems after solving the old ones.

Os Métodos Ágeis surgiram no final da década de 90, como uma alternativa aos métodos prescritivos de desenvolvimento de software. Eles propõem uma nova abordagem de desenvolvimento, eliminando gastos com documentação excessiva e burocrática, enfatizando a interação entre as pessoas e as atividades que efetivamente trazem valor ao cliente. Nos últimos anos, diversos princípios e práticas baseados na indústria de manufatura foram incorporadas pelos Métodos Ágeis de desenvolvimento de software. Um dos princípios absorvidos é o de melhorar a eficácia de uma organização através de melhorias globais. Embora este princípio seja bem difundido nos Métodos Ágeis, utilizá-lo não é uma tarefa fácil. Nem sempre é fácil ter uma visão global do processo de desenvolvimento. Além disso, para realizar melhorias globais é necessário descobrir a causa para possíveis problemas, o que também pode ser uma tarefa difícil. Esse trabalho investiga duas abordagens da indústria de manufatura que enxergam uma organização como um sistema no qual todas as partes são inter-relacionadas. Com base nelas, três abordagens de desenvolvimento de software existentes são analisadas. Finalmente, um estudo comparativo foi feito para avaliar as principais características dos métodos de desenvolvimento estudados. Esse estudo estende o trabalho feito por Abrahamssom et al., no livro Agile Software Development: Current Research and Future Directions, avaliando o desempenho dos métodos seguindo o arcabouço proposto pelos mesmos autores. / Agile methods appeared in the late 90\'s as an alternative approach to the classic prescriptive planning approaches to software development. They propose a new style of development, eliminating excessive and bureaucratic documentation, and emphasizing the interactions between people collaborating to achieve high productivity and deliver high-quality software. In the last few years, several principles and practices based on the manufacturing industry were incorporated by Agile software development. One of the principles absorbed is to improve the effectiveness of an organization through an overall improvement. Although this principle is quite widespread in Agile Methods, using it is not an easy task. It is not easy to get the big picture of the development process. Moreover, to achieve overall improvements is necessary to discover the cause of possible problems, which can also be a difficult task. This work investigates two approaches in the manufacturing industry that shares the assumption that the whole organization is focused on overall throughput, not on micro-optimization. Based on then, three approaches to existing software development are analyzed. Finally, a comparative study was done to assess the main characteristics of the studied methods. This study extends the work done by Abrahamssom et al. In the book Agile Software Development: Current Research and Future Directions, evaluating the performance of the methods following the framework proposed by the same authors.