IEC 61280-2-11 pdf download – Fibre optic communication subsystem test procedures – Part 2-11: Digital systems – Averaged Q-factor determination using amplitude histogram evaluation for optical signal quality monitoring
• Operation/maintenance: to engage the system for provision of operational service and to sustain the prescribed level of system performance capability.
• Enhancement: to improve the system performance with additional features.
• Retirement/decommission: to end the existence of the system entity. The description of system life cycle stages in Figure 2 is viewed from a generic systems engineering perspective. There are other system life cycle descriptions. IEC 60300-2 describes the product life cycle phases from a project management view.
ISO/IEC 1 5288 provides a similar system life cycle description from a software engineering view. Whereas there are some differences in the use of terms presented in these standards, their alignments are noticeable at the transition points of their respective system life cycle stages or project phases. Each stage has its own specific objectives to be met by the system design process, such as limited access to maintenance during system operation, recyclable parts for ease of disposal. Each stage also requires different internal procedures and work instructions, as well as requiring different contractual conditions to be met. Defining system requirements and developing system solutions during concept/definition and design/development stages can affect subsequent stages in system operation/maintenance. Decisions made for system architecture and technology selection in system design can have an effect on production, system integration and enhancement efforts, and constraining the disposal process. The time duration of a system life cycle is affected by various factors depending on the system type and application, the technology used, and the support provision. For example, the life cycle of a motor vehicle may last from 7 to 1 5 years due to mechanical wear and chassis deterioration, whereas a personal computer may have a life-span of less than 5 years due to technology obsolescence.
The time duration for application is the useful life of the system. 4.3 System operation The primary objective of a system design and application is aimed at achieving its intended performance during system operation. The operation stage of the system life cycle represents the useful life or service life of the system. During operation the system is monitored, maintained, and supported as needed to sustain operational objectives. For most system operations, they follow a generic operating pattern of average usage reflecting the actual application. The functions during operation are needed to carry out the intended system performance all the time or to be available upon demand to meet performance requirements. In some cases, there is a warranty period representing a sub- stage during initial operation of the system. During guarantee and warranty periods, the system maintenance and support effort may be more intensive for business or contractual reasons than those normally applied after warranty for the remaining useful life of the system operation. Most commercially available systems, such as a motor vehicle or a home entertainment system, fit into this generic pattern for operation and maintenance. However, there are systems designated for serving a dedicated operational objective where a specific operating profile will need to be established. Degradation in system performance should be presented by a separate operation stage. Under normal system operation, degraded performance of system without affecting critical operation is tolerated up to a predetermined limit. For example, a few isolated outage incidents of subscriber lines of a telecommunications switching system due to infrequent lightning strikes in bad weather conditions is normally considered acceptable.
The general public customers would tolerate such rare events subject to expedient restoration to full service within reasonable time. However, the occurrence of outages in such rare events still represents a degraded performance scenario. Degradation will have an effect on the quality of service provided by the system. Emergency situations and responses should be treated as separate stages.
IEC 61280-2-11 pdf download – Fibre optic communication subsystem test procedures – Part 2-11: Digital systems – Averaged Q-factor determination using amplitude histogram evaluation for optical signal quality monitoring
