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    Introducing cost-effective technology into a small New Zealand manufacturing company : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Manufacturing and Industrial Technology at Massey University
    (Massey University, 2001) Caukill, Mark
    Precision Manufacturing Limited (PML) is a small general engineering firm in Feilding, New Zealand. It is a general job shop (with a few specialty products) well known in the region for producing timely, high quality results. Southchain Conveying Systems Limited was purchased in November of 1998 and is the only conveyor chain manufacturer in New Zealand. Soon after taking over Southchain, the company found it difficult to compete against chain imports in the New Zealand conveyor chain market with a manual operation. At this point in time Precision Manufacturing owner, Garth Thelin, contacted Massey University and the idea of a GRIP project was introduced. The project commenced on November 1 1999 and ran for 14 months. The technical goals of the project were to reduce manufacturing costs by 30% and limit capital expenditure to $100,000. A numerical process model was built using Microsoft Excel based around a combination of a Bill of Materials model and a Route Sheet model. After completing the proccss model, it was then analysed to obtain a list of first order savings projects in the company. Dollar savings vs. the estimated cost of implementation, as well as interdependencies between the issues, was used as a criteria to rank projects as first order. Two projects were then chosen to be pursued: pin induction automation and roller induction heat treatment. The induction automation project covered the design of the mechanical apparatus, building and testing of working models, building of the production machinery, and the industrial control systems to integrate the mechanics to the induction heater. The roller induction heat treatment project investigated using the in-house induction heater to case harden the chain rollers and divest the company of a high external expense. Six months after the project was completed the company had reduced its costs considerably and as a result, was more profitable. The key to this was the reduction in roller costs. With better margins the company has been able to increase its sales and hence boost production levels. Being more profitable also means the company is in a better position to implement more cost saving measures and become more competitive in the market place.
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    A simulation study of the effects of applying JIT manufacturing techniques in a job shop environment with Kanban-based production control : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Production Technology at Massey University, Palmerston North, New Zealand
    (Massey University, 1999) Li, Jing-Wen
    Just-in-Time (JIT) manufacturing has long been considered effective for improving the performance of job shop manufacturing. For application in a job shop environment, the most often suggested JIT techniques include: cellular manufacturing, processing and transporting parts one at a time (i.e. single-unit production and conveyance), demand-pull production control with the Kanban (i.e. a visual signal), employing faster material handling facilities, and reducing the variability of setup / processing time. However, how and to what extent these suggested JIT techniques can affect the performance of job shop manufacturing is still not well explored. Accordingly, the motivation behind this study was to gain more understanding of the effects of implementing the suggested JIT techniques on the production performance in a job shop environment. Two simulation experiments were carried out to investigate the effects of five influential factors that are related to the application of the JIT techniques in a job shop. The findings through this study show that functional layout was more suitable for a Kanban-controlled job shop when the achievable amount of setup time reduction through the use of cellular manufacturing was small. On the other hand, if a large setup time reduction was achievable through cellular manufacturing, cellular layout should be adopted. As for a medium amount of setup time reduction achievable through cellular manufacturing, the performances for the two layouts were similar, except that cellular layout was more suitable with a medium to low setup time variability. Although the use of single-unit production and conveyance (SUPC) in cellular layout had been emphasised by many JIT proponents, we found that SUPC was only suitable for a Kanban-controlled job shop with unidirectional intra-cell production flow and a large amount of setup time reduction achievable through cellular manufacturing. The effects of material handling speed and variability of setup / processing time were not as essential as those of other influential factors. Therefore, to attain better performance for job shop manufacturing with Kanbans, employing faster material handling facilities and reducing setup / processing time variability should only be considered after the selection of appropriate shop layout and production flow patterns.
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    Model based analysis of the operation and control of falling film evaporators : a thesis presented for the degree of Doctor of Philosophy in Technology and Engineering, Massey University, Palmerston North, New Zealand
    (Massey University, 2000) Winchester, James
    Falling film evaporators are commonly used in the New Zealand dairy industry for the production of milk powders. Milk powder is not susceptible to bacterial damage and it is easy to transport, whereas milk itself has neither of these characteristics. As a result milk powders are an ideal export product for the New Zealand Dairy industry. However, despite their large amount of industrial use, there is a shortage of knowledge on the design, operation and control of falling film evaporators. The work discussed in this thesis was initiated with the aim of improving this situation. The aims of this work are split into three broad areas. Develop Model A first principles model for the Evaporator A plant at Kiwi Co-op Dairies will be developed from the Laws of Thermodynamics. The model is dynamic and includes the evaporator preheat sections. We will concentrate on developing the model for the subsequent analysis of the Evaporator A plant. Specifically, a steady state model will be developed for the optimisation/operation studies and a linear dynamic model for the controllability studies. Optimisation Studies Using the steady state model the operation/optimisation of the Evaporator A plant will be investigated. There are some simple aspects of the evaporator and preheat sections that will be discussed. However, an important aspect will be the evaporator operational optimisation with respect to energy costs, fouling, throughput and milk powder quality. Controllability Studies Using the dynamic model we will investigate the control of the evaporator plant. The dynamic model derived from first principles will be linearised to produce a linear constant coefficient dynamic model. This can be analysed using the standard traditional and some advanced control methods. Specifically we will be interested in disturbance rejection.