4.3.9. Interface Management Process
4.3.9. Interface Management Process
The Interface Management process assists the Program Manager ensure interface definition and compliance among the system elements, as well as with other systems. The Interface Management process helps ensure that developers document all internal and external interface requirements and requirements changes in accordance with the program’s Configuration Management Plan. Developers also should communicate interface information to their counterparts responsible for affected systems and system elements, and should plan for coherent testing to verify expected performance and ultimately operational performance.
Systems are composed of system elements, and may operate as part of larger systems of systems (SoS). The design, definition and management of the physical and logical interfaces, both internal (communications between system elements) and external (communications between the system and other systems), are critical to program success. Both types of interfaces have become increasingly important as system complexity has increased, along with demands for systems to operate in highly interdependent SoS environments (see DAG section 4.2.1.2. Systems of Systems). Interfaces play a critical role in all systems and systems of systems that interact to deliver a collective capability. Complex systems consist of numerous interfaces of various types. In the absence of effective governance, interface sprawl can result in degraded system performance, sustainability, and maintainability.
Explicit management of the definition, development, implementation, and test of internal and external interfaces, including any associated dependencies, helps ensure that systems operate as designed and meet stakeholder expectations throughout the life cycle. Interface management should consider programmatic issues (e.g., roles and responsibilities, funding, scheduling) in addition to the technical aspects of systems engineering (SE) and integration.
Activities and Products
Interface management is an iterative process: as knowledge of the system and system elements increases during design activities, verifiable lower-level requirements and interfaces are defined and refined. Developers should assess impacts of the originally defined capabilities and interfaces, performance parameter thresholds and objectives, and the overall system when defining and modifying interfaces.
The Program Manager and Systems Engineer should ensure that the program’s interface management plan:
- Documents the system's internal and external interfaces and their requirement specifications
- Identifies preferred and discretionary interface standards and their profiles
- Provides justification for selection and procedure for upgrading interface standards
- Describes the certifications and tests applicable to each interface or standard
- Is consistent with the program’s configuration management plan
The Program Manager and Systems Engineer should ensure that the developer documents all system interface requirements (see DAG section 4.3.5. Requirements Management Process), places them under appropriate levels of configuration management, and makes them available to the appropriate stakeholders. These documented interface requirements serve critical functions at all levels of the system throughout the life cycle, including:
- Developing functional and physical architectures
- Facilitating competitive bids
- Enabling integration of systems and lower-level system elements
- Supporting system maintenance, future enhancements, and upgrades
- Providing input data for continuous risk management efforts
The Systems Engineer responsible for interface management has numerous key tasks throughout the life cycle, including:
- Defining and establishing interface specifications
- Assessing compliance of interfaces among configuration items composing systems or SoS
- Monitoring the viability and integrity of interfaces within a system
- Establishing an interface management plan to assess existing and emerging interface standards and profiles, to update interfaces, and to abandon obsolete architectures
The Program Manager should establish an Interface Control Working Group (ICWG) composed of appropriate technical representatives from the interfacing activities and other interested participating organizations. The ICWG serves as a forum to develop and provide interface requirements, as well as to focus on detail interface definition and timely resolution of issues. In the SoS environment, external program offices and developers collaborate as members of the ICWG.
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