Development cycle Subject

When decisions are considered instigators of the development process, the nature of the available context for taking a decision becomes increasingly important. The requirement specification can serve as a frame of reference through the entire development cycle and as such is an indispensable part of that context. Throughout the development cycle, the subject of the decisions will change with respect to level of detail, level of aggregation, considered domains, etc. To support a well-substantiated decision, the expression of the requirement specification must ally with the characteristics of the decision at hand. As a structure for the alliance, three types of requirement specification can be discerned technical specifications, functional specifications, and scenario-based specifications. 

If the design is such that a system important to safety is dependent upon the rehable performance of a computer based system, appropriate standards and practices for the development and testing of computer hardware and software shall be established and implemented throughout the life-cycle of the system, and in particular the software development cycle. The entire development shall be subject to an appropriate quality assurance programme. 

The essence of Systems Engineering is that it is interdisciplinary, focuses on defining customer needs and required functionality early in the development cycle and is subject to a structured evaluation and feedback system as this cycle rolls out. The customer s needs and functionality requirements are input to the design and feasibility analysis of the project. Steps in the development cycle are evaluated at certain pre-defined moments and if needed adjusted. Such adjustments may... 

The descriptive account of the carbon cycle presented above is a first-order model. A variety of numerical models have been used to study the dynamics and response of the carbon cycle to different transients. This subject is an extensive field because most scientists modeling the carbon cycle develop a model tailored for their particular problem. 

Special formulations have been developed for cementing operations in arctic regions or for deep water applications [206,208,256,720,739,1792]. In low-temperature formations, wherein the cement is subjected to freeze-thaw cycling, freezing-point depressants must be added. Salts may serve as such, but traditional organic freezing-point depressants, such as ethylene glycol, also may be added [1022-1024]. 

In addition to normal compression set test conditions, usually 22 hours at 70 °C in a hot air oven, pharmaceutical elastomeric closures may be subjected to compression set conditions simulating steam sterilization cycles in an autoclave for 30 minutes at 121 °C. Also, sterilizing cycles employing ETO, radiation, or dry heat are used. Comparison data between formulations are used to develop compression set values that will identify potentially acceptable compounds under these conditions. 

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