Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Nebraska, Lincoln, 1989. / Includes bibliographical references (leaves 147-157).

Thesis, PlanB (M.S.)--University of Wisconsin--Stout, 2006. / Includes bibliographical references.

The development of manufacturing systems is faced with progressively tightening time frames, along with growing requirements on planning quality and engineering accuracy. These demands result from significant cost constraints, shortening of product life-cycles, increasing number of product variants and economic needs for rapid time-to-market. Thus, an efficient production ramp-up including the commissioning as the crucial part, becomes more and more important for engineering companies to stay profitable. Virtual Commissioning (VC) is widely considered as promising method to address the challenges associated with real commissioning, but the simulation model building necessary for VC is affiliated with considerable effort and required expertise. VC of manufacturing systems has been a research topic in academia and industry for far more than a decade. Positive results are reported from large companies e.g. from the automotive industry, which are mostly utilising the complex and costly suites of tools in the context of the Digital Factory, rarely from SMEs. However, in particular also SMEs are forced to improve their engineering and commissioning processes, but suites of tools and methodologies used in large companies are not reasonably transferable to SMEs. Rationale for the rare use of VC, besides its general complexity, are a high modelling effort to build the necessary virtual plant models and a lack of availability of methodologies for systematic implementation and reasonable execution of VC. Thus, the main goal of this research is the development of a new systematic simulation study methodology as general guideline for planning, implementation and execution of VC. It is intended to be notably beneficial for engineers from SMEs, as helpful guideline for planning, implementation and execution of VC and to facilitate the substantially high modelling effort required for VC of manufacturing systems. Besides clarifying the requirements and specifying an environment for VC, the criteria to select an appropriate simulation tool have been established. The proposed modular, component based simulation model building has been split into specified procedures for “Low-level Component Modelling”, to be conducted for the components of the decomposed real manufacturing system, and subsequent “High-level Plant Modelling” of the virtual manufacturing system. The applicability of these new approaches has been validated by planning, implementing and conducting a VC for a trackbound transportation system with self-driving transport cars on passive tracks, which is the major subsystem of the manufacturing system used as test-bed at the UASA Hannover. As one main result, a novel workflow for Low-level Component Modelling has been proposed that aims for the gradual relocation of this modelling task as far as possible to the origin of components, in the end the component manufacturers should provide together with the deliverable components their mechatronic component models. This is related to a novel proposal for exchangeable mechatronic component models and an outlined possible implementation with AutomationML.

The contribution to new knowledge from this research is a novel method for modelling production costs throughout the design phase of a product's lifecycle, from conceptual to detail design. The provision of cost data throughout the design phase allows management to make more accurate bid estimates and encourages designers to design to cost, leading to a reduction in the amount of design rework and product's time to market. The cost modelling strategy adopted incorporates the use of knowledge-based and case-based approaches. Cost estimation is automated by linking design knowledge, required for predicting design features from incomplete design descriptions, to production knowledge. The link between the different paradigms is achieved through the blackboard framework of problem solving which incorporates both case-baseda nd rule-based reasoning. The method described is aimed at innovative design activities in which original designs are produced which are similar to some extent to past design solutions. The method is validated through a prototyping approach. Tests conducted on the prototype confirm that the designed method models costs sufficiently accurately within the range of its own knowledge base. It can therefore be inferred that the designed cost modelling methodology sets out a feasible approach to cost estimation throughout the design phase.

The objective of this study is to assess the Lean Manufacturing practices by Transwerk Uitenhage and to reveal the barriers to implementation of lean manufacturing strategies experienced by their supply line. This will be compared to what the literature says and suggestions to overcome these barriers will be developed.

For many manufacturing companies, equipment is the largest capital investment andeffective maintenance of these assets can impact on profitability. It extends equipment life, improves equipment availability and retains equipment in proper condition. Conversely, poorly maintained equipment may lead to more frequent equipment failures, poor utilisation of equipment and delayed production schedules. Malfunctioning equipment may result in scrap or products of poor quality. Total productive maintenance (TPM) is one of the most popular concepts for improving process dependability (Nakajima 1988). It focuses on increasing the effectiveness of maintenance which is commonly measured by the overall equipment effectiveness (OEE). Ford Struandale Engine Plant (FSEP) applies lean manufacturing through its Ford Production System (FPS) which consists of twelve elements. One element of FPS is Ford Total Productive Maintenance (FTPM) with the objective to maximise the overall effectiveness of plant facilities, equipment, processes and tooling through the focused efforts of work groups and the elimination of the major losses associated with manufacturing equipment. The concern for FSEP management was that although FTPM is implemented, the OEE data revealed that equipment availability targets are not achieved. The researcher identified a gap to investigate the reasons for the poor performance. A literature study was conducted to search for relevant information on the subject. A questionnaire was constructed from the theoretical information and a survey was conducted. After data collection the results were captured and analysed. The researcher made conclusions based on the data and made recommendations. The main findings were that autonomous maintenance is not functioning well, spares management is not good and the Computerised Maintenance Management System is underutilised. The recommendations were that these issues must be addressed.

Asset Management, which evolved from maintenance management, is a set of processes, tools and measures that provide a shared understanding of an organisation’s physical assets. The process of asset management involves creation of a register of assets and recording of details of planned work. It also covers scheduling and recording of work done in order to create financial and technical history of assets. The life cycle of an asset consists of the acquisition operation, maintenance and disposal phases. These four aspects of an asset’s life represent the high level framework for asset management. This framework is crucial in development of asset management plans. The plan in turn, creates a road map for asset management excellence. By optimising the performance of asset management practices and processes a positive contribution can be made to the profitability of an organisation. The objective of this study was to develop a plan for the Coega Development Corporation (CDC) that would assist in management, maintenance, tracking and replacement of assets. The research primarily focused on the asset management requirements within the organizational context. The methodology employed in the study included a review of the relevant literature and case study conducted at CDC. The case study approach was very appropriate as it dealt with the current situation at CDC. Primary data was collected through interviews. Secondary data was collected from books, journals and other sources. Data was collected in words instead of numbers. The findings show that the CDC does not have an Asset Management Plan which results into the lack of information in the current asset register, a lack of specialist information systems, a lack of resources and an absence of a planning function in the skills sets of various units within the organisation. The Asset Register should work as a basic system for management of assets. The findings show that asset management can be used to comprehensively address the relevant elements of the organisations’ assets framework.

No description available.

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.