System life cycle

Every industry has its own way to define the system or product life cycle. For example, the facility construction industry life-cycle phases are requirements, planning, design, construction, activation, operation, and disposal. For purposes of discussion, the system life cycle is defined as (cradle to grave) follows  

Concept The idea of the project is hatched. During this phase, engineers develop an idea to accomplish the goal. More than one concept can be presented at this phase. 

Definition At this phase, the selected concept is amplified to exactly how the product or system is to be built. Preliminary design is performed. 

Detailed design The critical design is conducted. Detailed drawings and calculations are performed. 

Development The design is now mature and the system is constructed. As every engineer knows, there can be various iterations back and forth between the detailed design and development phases. 

Concept Concept design review Establish design for general evolution 

Definition Preliminary design review Establish general design for specific development 

Development Critical design review Approve specific design for production 

Production Rnal acceptance review Approve product for release in deployment 

Deployment Audit of operation and maintenance Control of safety operation and maintenance 

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The analysis of accidents and disasters in real systems makes it clear that it is not sufficient to consider error and its effects purely from the perspective of individual human failures. Major accidents are almost always the result of multiple errors or combinations of single errors with preexisting vulnerable conditions (Wagenaar et al., 1990). Another perspective from which to define errors is in terms of when in the system life cycle they occur. In the following discussion of the definitions of human error, the initial focus will be from the engineering and the accident analysis perspective. More detailed consideration of the definitions of error will be deferred to later sections in this chapter where the various error models will be described in detail (see Sections 5 and 6). 

All capital equipment decisions should be based on the true or life cycle cost of the system. Life cycle cost includes all costs that will be incurred beginning with specification development before procurement to final decommissioning cost at the end of the compressor s useful life. In many cases, the only consideration is the actual procurement and installation cost of the compressor. While these costs are important, they represent less than 20 per cent of the life cycle cost of the compressor. 

System qualification is a process that ensures that an analyzer system is installed and operated according to requirements that are aligned with the intended use of the system. The commonly used approach in the pharmaceutical industry is the system life cycle or SLC process. In the SLC approach, the definition of intended use, design, configuration, installation and operation is linked and documented over the lifetime of a system. 

Goals and Objectives of FEL The FEL work process must enable nearly constant consideration of changes as the work progresses. FEL phases must consider the long-term implications of every aspect of the design. Predictability of equipment and process system life cycle costs must always be balanced with operations and maintenance preferences, as well as the need for the project to maintain its profitability or ROI (return on investment). Additional important goals and objectives of FEL projects are as follows ... 

GMP risk assessment Qualified/trained resource System life-cycle validation System environment Current specifications Software quality assurance Formal testing/acceptance Data entry authorization Data plausibility checks Communication diagnostics Access security Batch release authority Formal procedures/contracts Change control Electronic data hardcopy Secure data storage Contingency/recovery plans Maintenance plans/records... 

Furthermore, the ISPE Baseline Guide, Commissioning and Qualification [5] emphasises the need to undertake qualification practices only for equipment and system component parts and functions that could directly impact quality attributes of a product or process. Other components and functions are to be dealt with under good engineering practice (GEP) [3,5] throughout the system life cycle, undergoing an appropriate level of documented commissioning. 

Good engineering practice—to establish engineering methods and standards that must be applied throughout the system life cycle to deliver appropriate, cost-effective solutions that underpin the validation program... 

Alignment of proposed system FDS with the URS System life-cycle development methodology and documentation Costs of proposed system Delivery dates and program... 

Computer systems validation, as established in 21 CFR Part 211.68, Automatic, Mechanical, and Electronic Equipment, is one of the most important requirements in FDA-regulated operations and an element of the system life cycle (SLC). In addition to the testing of the computer technology, other verifications and inspection activities include code walkthroughs, dynamic analysis and trace analysis. These activities may require 40% of overall project efforts. 

The system life cycle (SLC) is the period of time that begins when a product is conceived and ends when the product is no longer available for use. g... 

Figure 2-3. System Life Cycle focusing on Software Engineering Key Practices.

System Life Cycle (SLC) The period of time commencing from when the system product is recommended, until the system is no longer available for use or is retired. 

The system life cycle starts with the conceptualization period. This period is critical and is the highest level of design, and is primarily the responsibility of the system owner. The purpose of the conceptualization period is to establish an integrated model of the operation to be automated or re-engineered. This model provides the criterion to company senior management, enabling them to make a business and/or regulatory decision on whether to continue with a project. 

He is a practitioner with valuable experience in tackling real challenges and dealing with real-life problems. In this book, he illuminates the role of quality assurance, and shows the importance of integrating the validation activities into the system life cycle within a structured top-down approach. 

VMP for its successful execution. Reference the location of each deliverable and provide the detail necessary for retrieval at a later date (e.g., SOP and protocol numbers). Identify any conditions surrounding the use of the system. Were some features of the system found to be unsatisfactory for use Clearly state what aspects of the CRS are not approved for use until they are re-engineered and tested and what formal controls are in place to enforce this (SOPs, security programming, etc.). Design the VMP so that approval of the MVS document is the end point that releases the CRS for GMP use by appropriately trained users. This end point is called system acceptance and signals the transition to the validation maintenance phase of the system life cycle. 

ISO ISO 14043 Environmental Management Systems—Life Cycle Assessment—Life Cycle Interpretation ISO 14043 2000(E) International Organization for Standardization Geneva, March 1, 2000, 2000. 

Validation must employ predefined procedures and plans designed to build in quality during all stages of the computer system life cycle. The effectiveness of these procedures must be assessed periodically and improvements made as required. 

The risk assessment process can be conducted by examining record types to see if they are GxP or non-GxP, and then applying severity checks, likelihood, and probability of detection criteria, as illustrated in Figure 15.2. The most severe scenarios shonld be linked to direct patient/consnmer impact. GxP noncompliance and broken license conditions are severe in their own right bnt not as critical as patient/consumer health in this analysis." Its likelihood will be influenced by the degree of human error in how the record is input and used. The probability of detection needs to take into account the probability of the impacted record being used. Once failure modes are understood, then the appropriate design controls can be introduced. These should be documented and validated as part of the computer system life cycle discussed earher in this book. 

Demonstrate that validation is not an exercise at the end, but is integral to achieving good practice throughout the project and system life cycle. 

Evidence of sufficient control of these issues should be demonstrated in the validation documentation. Compliance must be integrated using a formal methodology and an appropriate system life-cycle approach that is clearly identified in the user requirements phase for any new computerized systems. The priority for validation activities can be established by analyzing the control scheme system and subsystem inventory for the criticality, validation stams, software category, and system type. This analysis aids validation planning and prioritization. 

The Validation Plan indicates the beginning of the validation project System Acceptance indicates that a system is validated. The system life cycle moves into the Operation and Maintenance phase. The System Acceptance documents often consist of a checklist, punch lists, and a summary report (commonly known as the Validation Report). 

Identify security requirements and attributes during the requirements phase, establish access control guidehnes during the design phase, challenge security features during the test phase, and routine audit security measures during the operation and maintenance phase of the system life cycle. Use procedures for maintenance of accounts and access authorization after system acceptance and as described in the operational system support procedures. 

Any modem EDMS system will generate a comprehensive set of user requirements and equally detailed functional specifications. It is therefore crucial to build traceability controls into the project documentation from the very start. Tools such as documentation matrices and requirements trace-ability matrices should be used to keep track of the necessary interrelationships throughout the system life cycle. 

Part 11 as Integral Part of System Life Cycle... 

Once the project is completed, the aspects of Part 11 have to be integrated routinely into the system life cycle management. During the system life cycle Part 11 impacts on several steps ... 

The transition from the project to routine should be accompanied by training of all parties included in the system life cycle. The training programs for computer validation and change control should be amended by the aspects of Part 11, so that there is a comprehensive understanding of what the implications of Part 11 are when implementing and maintaining systems. 

The validation of computer systems in the U.S. FDA-regulated environment is an ongoing process that is integrated with the entire System Life Cycle (SLC). Quality to a software system is introduced by following the system life cycle and following the key validation elements. 

Once in place, an LIS must be supported, and maintained. Software modules and operating systems may have to be upgraded and synchronized. Interfaces to laboratory instruments and communication links with clinical systems also frequently require upgrading and support. Although one might hope that an LIS could evolve gracefully and not require replacement, in practice all information systems inevitably become obsolete, and a new system life cycle begins. 

As far as possible, systems existing in a production mode prior to the effective date of the GALP standards, as well as purchased systems, should be documented in the same way as systems developed in accordance with the EPA System Design and Development Guidance and Section 7.9.2 of the GALPs. Documentation relevant to certain phases of the system life cycle, such as validation, change control, acceptance testing, and maintenance, should be similar for all systems. 

V-Model defines a uniform procedure for IT product development. It is designed as a guide for planning and executing development projects, taking into account the entire system life cycle. It defines the results to be achieved in a project and describes the actual approaches for developing these results. 

US EPA, Office of Solid Waste Emergency Response, "System Life Cycle Management Practice Paper on Expert Systems " Washington, DC, 1989. 

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