Aggregate production planning models are of the greatest importance to operations management, since these plans enable management to utilize the major resources at its command. In this report the structure of the aggregate planning problem and a number of different approaches are reviewed and presented. Approaches are classified in three categories: a) workforce smoothing models, b) production smoothing models, c) production and workforce models. The models are compared with respect to the cost structure, parameters estimation, forecast requirement, decision variables, computability and optimization techniques.

Production planning is an important activity in manufacturing industries. The main goal of production planning is to minimize the cost under the condition that the customer requirement in terms of quality, quantity, and time is satisfied. An important player (human) is with little attention in traditional production planning. This thesis studied production planning with consideration of human factor, especially human work injuries as a result of performing a repetitive operation for a certain period of time in production systems. Production planning in this thesis only takes the minimization of total production cost as its goal. A linear programming technique was employed to incorporate the cost of work injury into the total production cost model. The LINDOTM software was used to solve the linear production planning model and to analyze the solution. Finally, the benefits of the production planning, which considers work injury, were discussed. Several conclusions can be drawn from this study: (1) the traditional production planning model, which only takes the material costs and labor costs into account, cannot deal with the cost related to work injury; (2) the work injury cost could be significant in those manual-intensive assembly systems, especially with high production rates; (3) the careful design of the worker’s postures can significantly reduce the work injury cost and thus the total cost of production. The significant contributions of this thesis are: (1) the development of a mathematical model for the total production cost including the work injury cost and (2) the finding that the work injury cost may be a significant portion in the total cost of production in the assembly system that has intensive manual works.

M.Com. / Please refer to full text to view abstract

Thesis. 1979. Ph.D.--Massachusetts Institute of Technology. Alfred P. Sloan School of Management. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND DEWEY. / Bibliography: leaves 152-154. / Ph.D.

The implementation of concurrent engineering into many large companies has greatly improved their product development processes. These companies have seen significant gains in quality and customer satisfaction with reduced product costs, defects, and time-to-market (Lake, 1992). Many large companies have successfully employed this relatively new product development philosophy. However, smaller companies have not yet integrated this philosophy into their product development systems with the success that larger companies have seen. With small companies composing 98% of the manufacturing firms in this country (U.S. Census Bureau, 1995), there has been a recent push for the development of implementation methods for small companies. This paper presents a five step approach that small manufacturing companies can use to implement a concurrent engineering based product development process. Our definition of a small manufacturing company is an organization with 50 or fewer employees and net annual sales of 10 million dollars or less. The first step provides a general outline for companies to use in documenting their current product development process. The second step involves comparing the company's current product development process to a concurrent engineering based product development process model that is general enough for nearly all manufacturing firms. This step also includes the use of the theory of constraints and a so-called revised theory of constraints method to further refine the process understanding and description. Third, a new methodology for designing and applying process measurements is used to provide insight into the relationships that exists between the internal and external resources, requirements and deliverables of the product development process. It is during this step that the Process Measurement Matrix (PMM) is developed. Fourth, the PMM is used in conjunction with the analytical hierarchy process or a simple ranking technique to develop relative priorities. Finally, the appropriate measurements are constructed for each subprocess in the product development process. / Graduation date: 2001

Thesis (M. Phil.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Thesis--PlanB (M.S.)--University of Wisconsin--Stout, 2004. / Includes bibliographical references.

Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references (leaves 146-154). Also available in electronic version. Access restricted to campus users.

Thesis (M. Phil.)--University of Hong Kong, 2002. / Includes bibliographical references (leaves 56-58).

Timely provision of quality products at the lowest prices possible has become the utmost competitive edge being pursued by virtually all manufacturing firms. They endeavour to speed up their production and deliveries of goods to end customers in order to make more money and even survive in the fierce competition arena. Although much progress has been made in operations management and a series of production planning approaches have been proposed to achieve various manufacturing operations goals, optimisation results are often rendered unrealistic and even misleading, for few studies have considered the overall corporate goal of shareholder wealth maximisation and the specific economic environments where manufacturing firms operate. Some critical factors closely related to interests of corporate owners, such as working capital management and capital structure, are rarely involved in an overwhelming majority of production planning problems. Moreover, the overlook of the effects of production planning results on the environment makes them more impractical and even unavailable in real-world manufacturing environments. To this end, the dissertation proposes a stochastic production planning model for the uncertain make-to-order production environment, with the focus mainly on the lot sizing decision-making policy. The primary goal of the optimization problem is to maximise the sustainable full interests of corporate owners, namely, the shareholder wealth, rather than to optimise some traditional local or short-term objective functions, such as work flow times, accounting costs, accounting profits and the like. To improve the generality and exactness of the proposed model, all involved uncertain random events are characterized by their own inherent statistical merits without any impractical assumptions on their distributions. The improvement of production planning is not the only one single source of the wealth-based business performance. There are also some other critical factors which can impose direct influences on shareholder wealth. Among these potential shareholder wealth drivers, we choose to examine the effective management of working capital and capital structure, for they are closely pertinent to a firm’s financial position and its cash flow status. In addition, environmental protection has in recent decades aroused extensively global attention because of its far-reaching impingements on the social and economic developments of the world. The carbon emission in production, especially its main component—carbon dioxide, is generally recognized as the most important emission source. To mitigate their diverse interference with the climate and the environment, a wide range of emission reduction measures, laws, and legislations has been enacted and implemented, making production planning optimisations more complicated. To better reflect the emerging production planning environment facing manufacturing firms, the emission trading system for carbon management, which has thus far become the most popular market-based carbon reduction mechanism, is incorporated into the proposed production planning model. To theoretically and analytically validate the proposed approach, the probability and convex theories are adopted to prove the convexity or concavity of the optimisation objectives and the relevant global optimal characteristics. Numerical experiments are further conducted to demonstrate the important implications of the proposed optimisation model to production planning in industrial practices. / published_or_final_version / Industrial and Manufacturing Systems Engineering / Doctoral / Doctor of Philosophy