Product life-cycle failures

Packaging trends involve lower cost, more functionality, volume growth, shorter product life-cycles and increased value. Rigid plastic packaging now dominates markets which were previously the exclusive realms of materials such as glass and metal, despite the fact that some technical aspects of plastic are still inferior to those of such traditional materials, e.g. the failure of plastics to withstand high temperatures without deforming, or barrier properties of a standard comparable to that... 

In principle, it is possible to differentiate the damage behavior regarding the product life cycle into three superior damage phases Early failure phase, coincidence failure phase and wearout failure phase. The serial combination of these phases ( bathtube curve ) is shown in Fig. 1, focused on the failure rate 7.(t). Furthermore, Fig. 1 includes the range of the WeibuU form parameter b in reference to the failure phase. 

Figure 1. Schematic failure rate k t) during the product life cycle including fundamental superior damage phases. 

Based on the statistical prognosis and the specifications of possible damage during the product life cycle in the early phase of product construction, it is feasible to conclude actions to optimise the product and its subcomponents. The actors OEM and supplier of the value added network benefit primarily from this information, because they can optimise their products and subcomponents. Furthermore, it is possible to reduce technical failure analysis costs through drawing selected samples of damaged components out of the field. 

The lEC 61508 is a generic standard for elec-trical/electronic/programmable electronic (E/E/PE) safety-related systems. It should be applied from the concept rmtil the disposal or decommissioning of the product if a possible failure of a system can lead to hazards for humans and/or the environment. During this product life cycle the application of the lEC 61508 is ordered using an overall safety lifecycle. The standard is a generic standard and thus is used to derive domain specific standards as described in section 1. 

Supply uncertainty Free exchanges of information - starting with the product development stage and continuing with the mature and end-of-life phases of the product life cycle - have been found to be highly effective in reducing the risks of supplier failure. 

The information recorded on the PHA worksheet, together with the PHA report, will greatly facilitate the performance of other benehcial system analyses (such as the subsystem hazard analysis, the failure mode and effect analysis, and the operating and support hazard analysis) that may be accomplished during the remaining phases of the product life cycle. 

The failure mode and effect analysis (FMEA) is one of the more familiar of the system safety analysis techniques in use. It has remarkable utility in its capacity to determine the reliability of a given system. The FMEA will specifically evaluate a system or subsystem to identify possible failures of each individual component in that system, and, of greater importance to the overall system safety effort, it attempts to forecast the effects of any such failure(s). Because of the FMEA s ability to examine systems at the component level, potential single-point failures can be more readily identified and evaluated (Stephenson 1991). Also, although the FMEA should be performed as early in the product life cycle design phase as possible (see Figure 3.4), based on the availability of accurate data, the system safety analyst can also use this tool, as necessary, throughout the life of the product or system to identify additional failure elements as the system matures. 

Cromheecke, M.E., F. Koomneef, G.L. van Gaalen, B.A. de Mol (2000). Controlling risks of mechanical heart valve failure using product life cycle-based safety management. In Vincent Ch, B.A. de Mol (Eds). Safety in medicine. Elsevier Pergamon, Oxford, 2000, pp 1-21. 

The analysis of product failure behaviour and reliability parameters concerning the products life cycle is fundamental within the early product development phases. Initial measurements regarding the analysis of product reliability characteristics are based on prototypes. The challenge is the comprehensive analysis regarding the detection and mapping of expected failure modes and failure behaviour. Based on this analysis, product and manufacturing process optimisation is feasible. 

A unique aspect of the "E/E" market is the fast "time-to-market" demands of the industry—usually six months or less—and relatively short product life cycles, perhaps 12 to 18 months. These considerations virtually preclude multiple sourcing of materials and parts other than the most basic of units, such as connectors. They also mean that suppliers must work with end users with new applications from the beginning—for which they will be rewarded with the business—but they will be unable to displace or even share business with an existing supplier unless there has been a major quality failure. 

Measures to minimize safety problems must be initiated at the start of the life cycle of any product, but too often determinations of criticality are left to production or quality control personnel who may have an incomplete knowledge of which items are safety critical (Hammer, 1980). Any potential non-conformity that occurs with a severity sufficient to cause a product or service not to satisfy intended normal or reasonably foreseeable usage requirements is termed a defect (Kutz, 1986). The optimum defect level will vary according to the application, where the more severe the consequences of failure the higher the quality of conformance needs to be. 

Consider a product whose product cost is Pc. The costs due to failure at the various stages of the product s life cycle have been investigated, and in terms of Pc, they have been found to be (Braunsperger, 1996 DTI, 1992) ... 

There exists a relationship between the failure characteristics of a product over its life-cycle, as described by the three periods of the bath-tub curve above, and the phenomenon of variability. It has already been established that the potential for variation in design parameters is a real aspect of product engineering. Subsequently, three major sources of undesirable variations in products can be classified, these being (Clausing, 1994) ... 

Process Reliability Simulation VIP The process reliability simulation VIP is the use of reliability, availability, and maintainability (RAM) computer simulation modeling of the process and the mechanical reliability of the facility. A principal goal is to optimize the engineering design in terms of life cycle cost, thereby maximizing the project s potential profitability. The objective is to determine the optimum relationships between maximum production rates and design and operational factors. Process reliability simulation is also applied for safety purposes, since it considers the consequences of specific equipment failures and failure modes. 

Throughout the product or service life cycle, deterioration is likely to occur. Components wear out, materials become damaged or lose their effectiveness. In the service realm, human error and inconsistencies contribute to process variation and deterioration. To reduce the impact of these factors on performance, use Design FMEA (Technique 40) to flag areas that are susceptible to wear or failure, and then design your product or service to avoid or withstand deterioration as much as possible. 

Unlike the production-oriented economic animals (poultry, swine, cattle, fish, and shrimp) pets typically are allowed to live their full life cycles, and thus experience problems of aging, including kidney, vision, backbone, and hip failures, and obesity if food intake is not adjusted to the animal s activity level. Special puppy, kitten, and life-cycle series pet foods have been marketed. 

Under the new paradigm for decision making, all decision makers will increasingly be forced to take into account the perspectives of the other players affected by their decisions. Prescribers will no longer consider just the clinical impact, but also the economic impact their decision will have on the payer, and the QOL impact the decision will have from the patient s perspective. The payer and patients will need to consider the impact of their decisions on the rest of the system. Successful drug developers now evaluate three-dimensional outcome data as early as possible in the product development life cycle. This information will also be useful to investors who are making decisions regarding the ultimate potential for success or failure of a newly discovered therapeutic product. 

The quantitative assessment of environmental impacts can be made using life-cycle assessment (LCA) methodology, which accounts for both inputs and emissions. LCA can be used to identify the major environmental impact categories and the sources of those impacts within a chemical processing plant. LCA can also be used to identify the major contributions to environmental impact within a product s life cycle. Impact scores derived from LCA can be used along with economic assessment scores and social indicators to provide indicators of overall sustainability of processes and products. Economic assessments are often limited through failure to account for all internal costs and especially the external costs associated with waste. 

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