This study presents the results of using common two or three-parameter "default" distributions in place of "best fit distributions" in simulations of serial production lines with finite buffers and blocking. The default distributions used instead of the best-fit distribution are chosen such that they are non-negative, unbounded, and can match either the first two moments or the first three moments of the collected data. Furthermore, the selected default distributions must be commonly available (or easily constructed from) distributions in simulation software packages. The lognormal is used as the two-parameter distribution to match the first two moments of the data. The two-level hyper-exponential and three-parameter lognormal are used as three-parameter distributions to match the first three moments of the data. To test the use of these distributions in simulations, production lines have been separated into two major classes: automated and manual. In automated systems the workstations have fixed processing times and random time between failures, and random repair times. In manual systems, the workstations are reliable but have random processing times. Results for both classes of lines show that the differences in throughput from simulations using best-fit distributions and two parameter lognormal is small in some cases and can be reduced in others by matching the first three moments of the data. Also, different scenarios are identified which lead to higher differences in throughput when using a two-parameter default distribution. / Graduation date: 2004

The objective of the thesis was to construct a deterministic single year, farm planning model that would enable vegetable producers to select an optimal farm plan from among alternative crops and crop production methods so as to maximize farm income consistent with technological and resource constraints and other goals. The model was to be readily adaptable to a wide range of commercial vegetable farmers in Canada but sufficiently flexible to be adaptable to the particular situation of a specific farm. A multiperiod linear programming model was built and validated through its application to a large commercial vegetable farm. The relevant theory of the firm was reviewed with special attention made to the theory's application to vegetable farms. The structure of a linear programming problem was discussed and related to the theory of the firm and vegetable farms. Special emphasis was placed on the problem of modeling the machinery used in vegetable production. The work of agricultural engineers was examined to determine the technological relationships involved in machine operation. Other crop budgeting models which involved the construction of similar planning models for a different sector of the agricultural community, especially the Purdue Crop Budgeting Models were reviewed. The model constructed was able to deal with machinery constraints by building a number of machine operating activities and tractor transfers so that the time constraint for a particular job would consist of any subset of the predefined set of time periods. Standard coefficients were prepared based on engineering formulae for fuel consumption and repair and maintenance costs for tractors. All inputs in the model except repair and maintenance costs were in physical units. This made it necessary to build several different types of purchasing or renting activities but facilitates the interpretation of data and the use of the model in a large number of different situations. The model was validated through its application to a large commercial vegetable farm in British Columbia. The model was run in simulation mode by forcing the model to follow the farm's 1974 crop plan and altering yields and prices to yields and prices that actually occured in that year. In this manner the reliability of the cost coefficients of the input data and the relationships between resources could be evaluated and compared with the results recorded in the farm's CANFARM records. The model was run in optimization mode with expected 1976 prices and yields to demonstrate the use of the model in selecting an optimal farm plan. A total of six plans were prepared based on alternate market and risk constraints and yields. These were compared with the plan selected by the farmer without the aid of the model. A detailed report on one of the farm plans v/as also prepared. / Land and Food Systems, Faculty of / Graduate

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Typescript, etc. / Digitized by Kansas Correctional Industries

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M.Comm. (Strategic Management) / The turbulent and swiftly changing business environment assigns very big requirements and challenges to managers of all enterprises. Because of the current political and constitutional process of reform, local authorities find themselves on the verge of dramatical structural change. Traditionally local authorities operated in a relatively predictable and inert environment. The turbulent and swiftly changing environment, together with the expected structural changes, assign unprecedented demands and challenges to the managers of local government. To enable managers to handle these requirements and challenges to the optimal benefit of their residents and businessmen, the advancement of strategic management is of utmost importance. This study is directed at the distinguishing of potential requirements and challenges that could be assigned to managers in local government and to local government's pressing need of strategic management. A discussion of the use of computerbased management simulation as support to strategic mana~ment training in local government is included in the study. The central purpose of the study is to distinguish different applications of management simulation as an aid to the promotion of strategic management in local government and to indicate the value thereof. Management simulation can successfully be used to provide managers in local authority with simulated experience of the practical application of strategic management theory. Managers get the opportunity of strategically directing a simulated local authority and in this way they can make decisions without the need to fear for the consequences of erroneous decisions. There is no doubt that management simulation can make a worthwhile contribution to the advancement of strategic management in local government.

The process analysis approach was chosen for modeling the joint product nature of timber supply. Considerable emphasis was placed upon defining model components that would be required for developing a positivistic model of timber supply. An empirical application of the proposed linear programming model to Eastern Virginia simulated the impacts of increased fuelwood prices on the timber market system in 1976. The empirical application of the model indicated an ability to simulate many of the complex market interactions inherent in timber supply. Fuelwood was found to act as both a production complement and a production competitor with the conventional forest products, depending upon the range of prices analyzed. Fuelwood price was also found to act as a demand shifter for roundwood outputs of the forest. / Ph. D.

A simulation model is developed in SLAM II to study and analyze conveyor systems.. The adequacy of the model is tested by applying it to a conveyor layout as well as some variant designs. 1he problem of modeling large systems is reduced by decomposing the system into smaller segments (subsystems). Different types of conveyors are considered. Programming modules are prepared for feasible conveyor types and segments. These simulation modules are integrated into a system. / Master of Science

Intermodal traffic has been steadily increasing on the nation's railroads since the mid 1950's. Intermodal flatcar activity is now second only to coal in terms of total car loadings throughout the industry. The intermodal segment of the nation's transportation system is expected to play an ever increasing role in the future. Intermodal managers faced with increasing demands on their systems, have expressed a need for methods to aid in the development of new management techniques, economic costing models, and management information systems. The computer simulation intermodal model that is presented in this paper is designed to aid managers with the analysis of their current terminal systems and to plan for future growth in intermodal activity. The intermodal terminal model employs discrete, next event, simulation techniques. The Q-GERT simulation language, developed by A. Allen B. Pritsker, provides the vehicle necessary to approximate the required activities and associated flow of transactions through the terminal system. Three specific types of containers and flatcars are provided for, in addition to provisions for over-the-road container pick up and delivery. Thus, the model is adaptable to complex terminal systems, including sea ports where highly specialized containers are commonly encountered with rail, truck and ship interfaces. It is possible to simulate terminal activities for any period of time required for a specific analysis. The model's simulation output can also be modified, with little difficulty, to provide estimates of specific variables of interest for a particular terminal. Provisions for the operating environment of a terminal are also included in the model. These include week-end work rules, switching rules, container consignee notification rules, types of handling equipment employed and the standard working hours for a terminal. The primary applications of the model are viewed to be in the areas of planning and analysis for intermodal terminal current operations and future design concepts. The graphical network orientation of the model, however, could provide managers with a communications tool to apprise upper level decision makers of new concepts. Current problems, with recommended solutions, could also be visually illustrated. / Ph. D.

A stochastic dynamic constituent transport model was developed, capable of simulating the operation of a water distribution system containing pumps and storage tanks, and subject to random demands and contaminant inputs. Long term operation of a hypothetical small town water supply system containing one pump station and one storage tank was simulated while the system was subjected to external contaminant inputs. Repeated simulations were made under different regimes of external contamination applied to the tank, the pump station and at system nodes, and internal contamination representing biofilm effects based on assumed relationships between flow velocities and bioflim cell detachment. Seven sampling plans representing regulatory requirements and industry practice were applied during the simulation to evaluate their ability to detect the contamination under a presence/absence criterion. The simulations were able to identify contamination patterns and provide information useful in the definition of sampling plans. Time of sampling was found to be as important as location. This was true both within the monitoring period, and particularly within the diurnal cycle of demand. Spreading samples over different days within the monitoring period rather than sampling all on one day, always improved contaminant detection. Detection by plans based on fixed times and locations were very sensitive to those times and locations. There was no best plan suitable for all situations tested. The better sampling plans were those that captured the temporal and spatial contamination patterns present in the system. No consistent advantage was noted from sampling in proportion to population served or in locating sampling nodes systematically instead of randomly. The location and timing of sampling for most plans could be improved with the knowledge of actual contamination patterns and timing provided by the model. The presence of a storage tank was found to have a strong influence on hydraulic patterns and the location and timing of contamination reaching different parts of the system. / Ph. D.