Life cycle modelling

During a forum convened by the World Wildlife Fund and the Conservation Foundation in May 1990, various steering committees recommended that a three-part life-cycle model be adopted. This model consists of the following ... 

I recommend that you follow a more traditional systems development life-cycle model (SDLC) when developing a comprehensive SAS macro-based reporting system. Unlike much of the one-time-only SAS programming that occurs for a clinical trial, you need to ensure that a general-purpose SAS macro system is robust enough to handle any problem it encounters. The systems development life-cycle approach to software development will help you to build strong software applications with SAS. 

Shlaer92] Shlaer, S., and S. Mellor. 1992. Object Life Cycles Modeling the World in States. Englewood Cliffs, N.J. Prentice Hall. 

Fig. 1 Life cycle model of biorenewable polymers according to European Bioplastics [6]...

All publications refer to some kind of life-cycle model, with a formal change control procedure being an important part of the entire process. 

When all the directly (and indirectly) affected items that require modification have been determined the components and functions of the system directly and indirectly affected by the change can be identified. At this point a review of the system GMP risk assessment(s) should be undertaken and the potential for revalidation addressed. Reference to the life-cycle model will identify the specification for each item and point to the qualification test procedure(s) that need to be considered. 

IT-Security includes the following processes, which are related to the corresponding phases of the IEC Life Cycle Model (in [nn], Figure 3). Following this concept, the complete security management life cycle can be considered and integrated in a holistic, unified model of parallel, equivalent activities ... 

Capello et al.16 applied LCA to 26 organic solvents (acetic acid, acetone, acetonitrile, butanol, butyl acetate, cyclohexane, cyclohexanone, diethyl ether, dioxane, dimethylformamide, ethanol, ethyl acetate, ethyl benzene, formaldehyde, formic acid, heptane, hexane, methyl ethyl ketone, methanol, methyl acetate, pentane, n- and isopropanol, tetrahydrofuran, toluene, and xylene). They applied the EHS Excel Tool36 to identify potential hazards resulting from the application of these substances. It was used to assess these compounds with respect to nine effect categories release potential, fire/explosion, reaction/decomposition, acute toxicity, irritation, chronic toxicity, persistency, air hazard, and water hazard. For each effect category, an index between zero and one was calculated, resulting in an overall score between zero and nine for each chemical. Figure 18.12 shows the life cycle model used by Capello et al.16... 

Validation is a defined program, which, in combination with routine production methods and quality control techniques, provides documented assurance that a system is performing as intended and/or that a product conforms to its predetermined specifications. When practiced in a life-cycle model, it incorporates design, development, evaluation, operational and maintenance considerations to provide both operating benefits and regulatory compliance [3]. 

Life-cycle models can be used to manage the elaboration of complex projects [1]. A simple but efficient model can be built up on the basis of a waterfall approach. This indicates that the project sequencing should be organized so as to avoid excessive feedback between phases, and in particular to upset the architectural design. More sophisticated approaches, such as V-cycle or spiral models, could be used to handle projects requiring more flexibility and uncertainty, as in the case of software technology. 

The management of design project can be ensured by adopting the life-cycle modeling approach, in which the key elements are recognizing the priority of conceptual tasks and minimizing the structural revisions. 

Abstract Knowledge of the complex life cycle of Phaeocystis is a key to understanding its role in marine ecosystems and global biogeochemistry. An existing life cycle model was modified and used to integrate understanding of the Phaeocystis... 

The conceptual model of this paper serves two functions by (1) providing a context for integrating what is known, and (2) defining observations and experiments to eliminate unknowns (Whipple et al. 2005a). Figure 1 graphically depicts how the Phaeocystis life cycle model and empirical studies conducted to address unknowns may be interrelated each experiment within our research group described below is denoted by an acronym... 

The life-cycle approach has attracted broad acceptance across the pharmaceutical and healthcare industries and can be refined to meet the needs of particular applications. Different organizations use variants of the life cycle, but the methodology of dividing a life cycle into phases remains the same. For instance some companies develop the subphases that are indicated in the phase descriptions above as distinct phases in their own right. The specific life-cycle model chosen does not really matter. Its constituent phases must, however, be clearly defined in advance, with entry and exit criteria for each phase and appropriate verification procedures to ensure the controlled completion of constituent phases. 

Some of the steps in the validation fife cycle will not be needed in some validation projects. For instance, the use of preferred suppliers for software and hardware products or services removes the need for repeated supplier appraisal and selection. Life-cycle steps, however, cannot be eliminated for packaged systems with embedded computer system systems purchased from, or subcontracted to, a vendor. The degree of redundancy in the life-cycle model used for validating existing computer system systems will be specified in the Validation Master Plan. 

A validation consultancy firm has conducted validation work for several North American and European pharmaceutical manufacturers and has developed a staffing life-cycle model. This firm s experience suggests that this model is rather generic, in that it seems to fit most computer system validation programs. It can be used to assess the total validation workload. Figure 3.8 shows that the staffing profile consists of three phases preparation, implementation, and maintenance. 

The overall computer validation strategy within the Validation Master Plan should be outlined, as well as the life cycle model to be applied and the validation procedures to be used. 

Any deviations and interventions to the pharmaceutical or healthcare company s Validation Plan or Supplier s Project/Quality Plan must be recorded, their impact on validation assessed, and their true cause investigated. Deviations and interventions may include changes to SOPs during validation, concessions on the acceptability of unexpected test results, or modifications to the life-cycle model to make it more appropriate. 

System vahdation is employed as a mechanism to estabhsh objective evidence that a system consistently performs according to its predetermined requirements, specifications, and quality attributes. The GAMP software categories provide some guidance as to activities that should be followed as a minimum to provide the objective evidence of the system meeting performance objectives. The complexity of the computerized system should determine the extent of this effort. There are many life-cycle models published that fadhtate the creation of this objective evidence. Acceptable life-cycle models will include phases for Define, Design, Develop, and Operate. 

FIGURE 26.2 A Typical Life-Cycle Model Based on GAMP 4. 

Table 1 Applied thermodynamics system delivers value at every stage of life cycle modeling, and throughout the enterprise Stage Value...

The design of the product system model, especially with respect to the system boundaries and what processes are included within these boundaries, can be decisive for what data are appropriate and the outcome of an LCA study. As one example different types of life cycle models can be designed to describe ... 

Fig 1 The Hewlett-Packard CAG product life cycle model. ITQS Information Technology Quality system... 

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