Trade-offs analysis

The process of updating the schedule is basically the same as that used in planning the shutdown. It is simply based on new information and deals only with the remaining portion of the shutdown. In some very large shutdowns, it may be desirable to perform time-cost trade-off analysis, resource leveling, etc., each time the shutdown CPM is updated. In many cases, however, the update will involve only the basic forward, backward and slack computations. These calculations will allow for development of a revised schedule. They will also identify the critical path that is likely to change over the course of the shutdown. 

Capacity Requirements The operating capacity of a transfer station must be such that collection vehicles do not have to wait long to unload. In most cases, it will not be cost-effective to design the station to handle the ultimate peak number of hourly loads. An economic trade-off analysis should be made between the annual cost for the time spent by the collection vehicles waiting to unload against the incremental annual cost of a larger transfer station and/or the use of more transport equipment. Because of the increased cost of transport equipment, a trade-off analysis must also be made between the capacity of the transfer station and the cost of the transport operation, including both equipment and labor components. 

Task 3. Develop Design Concepts Develop system layouts and conceptual designs for the 2 or 3 options selected in Task 2. Conduct a trade-off analysis for the critical design and performance factors. 

Ceroni, J. A. (1996), A Framework for Trade-Off Analysis of Parallelism, MSIE Thesis, School of Industrial Engineering, Purdue University, West Lafayette, IN. 

The designer of optical systems must base the selection of optical materials on a knowledge of optical, physical, thermal and mechanical properties. Frequently, the selection of the materials must result from a trade-off analysis as no one material has an ideal set of properties. This compilation of Optical Materials Properties Data Sheets summarizes the vital properties, needed to select an optical material for use in the ultraviolet, visible and infrared regions of the electromagnetic spectrum. Forty-nine materials are described in this conpilation and each sheet of two pages presents the properties of a particular material. The listed properties... 

The enterprise should define the scope of the trade-off analysis to be conducted. A trade-off analysis can be... 

Informal and formal trade-off analysis objectives, execution, data collection requirranmts, schedule of activities, analysis of results, and expected outcomes need to be fully defined. Each trade-off analysis is conducted for the purpose of selecting among competing alternatives to support customer needs, system effectivraiess, design-to-cost, or life cycle cost objectives within acceptable levels of risk. 

The enterprise establishes metrics for each criterion that characterizes how well various alternatives satisfy the criterion. In addition, the enterprise establishes weighting factors for each criterion, which distinguish the degree of importance to the trade-off analysis definition. Models (representative or simulations) are established, when needed, to support conduct of a formal or informal trade-study. The selection of models depends on the nature of the trade-off analysis, the development stage, the type of information needed, and the characteristics of interest for an alternative. Models should be vahdated prior to application in a trade-off analysis. 

The enterprise analyzes the costs to the enterprise and to the customer for alternative system approaches considered in a trade-off analysis or system effectiveness assessment. Life cycle cost analyses... 

System and cost effectiveness analyses are conducted on life cycle processes of manufacturing, test, distribution, operations, snpport, training, and disposal to support inclusion of life cycle quahty factors into system product designs, and to snpport the definition of functional and performance requirements for life cycle processes. The resnlts of these analyses are used in evaluating trade-off analysis alternatives and for effectiveness assessments of the system. 

The enterprise identifies safety and environmental impacts associated with system implementation. Applicable environmental laws and regulations should be identified, and the enterprise should ensure that these are complied with by any alternative solution. The enterprise completes an environmental impact and safety analysis to determine the impact on and by system products, and the impact of their life cycle processes on the environment, or to personnel. Use of materials, or generating by-products, which present a known hazard to the environment, are to be avoided to the extent feasible. Where not feasible, provisions must be provided for proper handling, storage, and disposal of hazardous materials or by-products. Results of these analyses influence trade-off analysis recommendations and assessments of system effectiveness. 

The enterprise quantifies the impact of identified risk factors on the system or alternative being considered based on exposure to the probability of an undesirable consequence. For system effectiveness assessments, each element of the system architecture developed to date is assessed to determine what can go wrong, and if it goes wrong, what impact it may have on the system. For trade-off analyses, risk levels assessed during fife cycle cost, system and cost effectiveness, and environmental impact analyses are prioritized and reported as part of trade-off analysis recommendations. 

The enterprise utilizes the results of trade-off analyses and risk-reduction planning information to recommend a preferred alternative to the decision maker. The enterprise should assess the trade-off analysis to assure that the methodologies and data collection instrumentation were sufficient to support a fair and complete evaluation. Each recommendation should be presented in terms of configuration and cost, schedule, performance, and risk impact. 

The enterprise documents the recommended trade-off altemative(s) with corresponding impacts and presents the results to the appropriate decision makers within the SEP activity who are making or requesting the tradeoff analysis. The final alternative selection is made based on the criteria established to judge a desirable solution. Key trade-off analysis activities, decisions, rationale, and recommendations are documented in the... 

The CE process must facilitate an appropriate trade-off analysis leading to product-process design optimization. Conflicting requirements and constraint violations must be identified and concurrently resolved. 

Barbir, F., Molter, T., and Dalton, L. (2005) Efficiency and weight trade-off analysis of regenerative fuel cells as energy storage for aerospace applications. Int. J. Hydrogen Energy, 30, 351-357. 

The telemetry link between the central hub and the remote processing nodes at CASY is a bidirectional radio frequency (RF) telemetry link. Note the telemetry link could also have been a hardwire or telephone link, however, a trade off analysis on the telemetry medium was performed and the RF link was determined to be the most desirable and cost effective approach. (A more detailed discussion of the trade off analysis of the telemetry link will follow). A bidirectional telemetry link was chosen because it allows data to be both transmitted and received at the CPIMS site as well as at the remote processing nodes. Thereby allowing the CPIMS to receive input status as well as initiate output controls commands. 

The importance of the rigorous cost trade-off analysis during the design of electronic products is underscored by the fact that about 60 percent of the manufacturing costs are determined in the first stages of the design process, when only 35 percent of the total design effort has been expended. 

Technology trade-off analysis balance of loss and gain in various domains performance versus cost. 

The formal technology trade-off analysis during the specification phase... 

Knights S (2008), Material Trade-off Analysis for Performance vs. Durability, and Impacts on System Design , Fuel Cells Durability and Performance 2008, Dec 11-12,2008, Las Vegas, NV. 

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