The six core mission assurance processes identified in the Mission Assurance Guide are supported by seven mission assurance disciplines. These provide the more technically oriented underpinning of mission assurance application and include engineering methodologies specifically geared toward system design validation and product verification.
Risk management is a structured approach to identifying and evaluating risk and risk-control measures and communicating mission threats to program stakeholders. It requires a vigilant focus on technical performance and should be executed and reported independently. It provides an overarching framework under which mission risk issues can be evaluated and handled. Risk management moves typically through four stages. The first, risk planning, consists of the up-front activities needed to execute a successful risk management program; it is a vital part of normal planning and management. The second, risk assessment, includes the identification of critical events and conditions and an analysis of their likelihood, consequences, and time frame. Third, risk handling is the process that identifies, evaluates, selects, and implements actions to reduce risk to acceptable levels. Lastly, risk monitoring involves tracking the progress of risk handling actions and making adjustments as needed.
Reliability engineering encompasses a set of analytical activities that cover the entire system life cycle. In the early program phases, it includes the development and validation of probabilistic system reliability requirements and design trade-off studies. During design development and production, it assists with the determination of component failure rates and development of probabilistic reliability models, analysis of failure modes and effects, identification and control of critical items, application of worst-case and parts-stress analyses, and analysis of accelerated life test data. Particularly critical is the assessment of failures during integration and testing and the implementation of measures to prevent failure recurrence. Early planning of a solid reliability assurance process will contribute to a robust system design and minimize the chances of late and costly detection of problems.
Configuration management seeks to control the technical hardware and software baselines of a program—the requirements, specifications, designs, interfaces, data, and supporting documentation. The goal is to ensure that the functional, allocated, developmental, test, and product baselines are consistent, accurate, and repeatable and that any changes to those baselines will be recorded and will maintain the same accuracy, consistency, and repeatability. Configuration management must begin in the conceptual phase and cover contract and program documentation. During the design phases, the focus is on ensuring that baselines are properly established and that configuration management is maintained at all levels during all design reviews, with well defined hardware and software configured items and change-control boards. These baselines must be updated to reflect design and part changes resulting from failures observed during tests.
Parts, materials, and processes (PMP) engineering seeks to provide a standardized set of qualified components from which to build a reliable product at a reasonable cost and risk. The mission assurance aspect starts with independently verifying that proposed contractual PMP requirements are consistent with the overall program priority and risk management approaches. In the planning phase, it must be verified that adequate PMP controls and procedures have been developed and applied across the program. In the implementation phase, it must be ensured that these controls and procedures are rigorously followed and that the program has indeed acquired robust components. PMP engineers must work closely with design engineers to prevent selection of parts and materials that are not readily available at the quality and reliability levels required. The PMP lists should be independently reviewed with respect to past performance of similar items. Past performance of selected suppliers should also be independently examined.
Quality assurance is the engineering and management discipline intended to ensure that a product meets the specified performance parameters. A well defined and properly implemented quality assurance program instills confidence that all quality requirements have been met through control of operations, processes, procedures, testing, and inspection. A wide range of skills and expertise is required to support these activities. These include a thorough familiarity with applicable standards for various types of parts, materials, and processes and their associated testing methods. A thorough comprehension of the underlying technologies is also required to ensure that selected parts or materials will meet performance needs and that manufacturing processes are qualified and reliable. Because of the diversity of expertise involved, a team of technical specialists is normally required.
System safety assurance applies engineering and management principles and techniques to control system hazards within the constraints of operational effectiveness, schedule, and cost. Safety is a fundamental system requirement. The preferred method to handle safety risks is to eliminate hazards by design. If this is not possible, the risk of mishaps should be reduced via safety features or protective devices. These include detection and warning systems to alert personnel of hazards and special training to counter hazardous conditions. A system safety management process provides effective implementation of safety and occupational health policies. To ensure that hazards are identified, all areas of design, development, manufacturing, integration, test, operation, and maintenance must be subjected to a systematic hazard analysis and risk assessment. Identifying different risk mitigations and their expected effectiveness is part of this risk management process.
Software assurance seeks to ensure that system software will meet performance requirements and user expectations and will be dependable, maintainable, and applicable to the user's operational environment. It entails verifying that the software architecture can accommodate future change and growth. Large software projects are usually developed in asynchronous, concurrent streams. At any time, these streams will be in different states and may need synchronization. Thus, software assurance includes analysis in acquisition planning to consider the phasing of software tasks. A software assurance plan should define tasks and roles such as requirements development, systems engineering planning, support for integration of requirements flow-down, analysis of performance and design alternatives, analysis of subsystem and system design and integration, investigation of design trades, cross-systems integration between programs, lessons learned, technology commonality, evaluation of systems interfaces, and other functions focusing on system integrity and reliability.