Requirements Traceability Analysis. Requirements Traceability Analysis and the Requirements Traceability Difference Matrix - When defining a system, requirements start with a high-level functional specification that eventually generates many lower-level hardware and software specifications. Each of the functional requirements ("parent requirements") within the high-level specs. have associated low-level requirements ("child" requirements) further describing the details of how the function is to be implemented.
A requirements Traceability Analysis is performed to assure that all requirements are implemented into the system as either hardware, software or both. An effective Traceability Analysis also should show the hierarchy between requirements, any differences between the "parent-child" functionality and if any requirements are "orphaned" otherwise, having no parent requirements. IDA has developed a new tool for representing all this information called a Requirements Traceability Difference Matrix. HW/SW Sneak Analysis. - Incorrect or imprecise labeling of system functions - e.g., system inputs, controls, display buses - that may cause an operator to apply an incorrect stimulus to the system.
Sneak Circuit Analysis (SCA) was developed in the late 1960's for NASA to verify the integrity and functionality of their designs. Electronic control systems at this time were designed with relays, vacuum tubes, diodes and resistors. They did not contain Integrated Circuits, microprocessors or software like modern systems. Isolating each function from the other functions was a challenge to these early systems because current could inadvertently flow through an unintended path causing false indications, glitches, unintentional outputs, etc. especially when interacting with the equipment throughout it's operational scenarios. Sneak Circuit Analysis was a useful tool to discover all these unintentional circuit paths and assisted in devising solutions to isolate each function.
IT Architecture. MIL-STD-498 - Software Development. MIL-STD-498 (Military-Standard-498) was a United States military standard whose purpose was to "establish uniform requirements for software development and documentation. " It was released Nov. 8, 1994, and replaced DOD-STD-2167A, DOD-STD-7935A, and DOD-STD-1703. It was meant as an interim standard, to be in effect for about two years until a commercial standard was developed. Unlike previous efforts like the seminal "2167A" which was mainly focused on the risky new area of software development, "498" was the first attempt at a truly comprehensive description of the systems development life-cycle. It was the baseline that all of the ISO, IEEE, and related efforts after it replaced. It was one of the few military standards that survived the "Perry Memo", then U.S. Methodologies[edit] Paragraph 4.1, “major activities may overlap, may be applied iteratively, may be applied differently to different elements of software...need not be performed in the order listed.”
Data Item Descriptions[edit] Technology readiness level. NASA Technology Readiness Levels Technology readiness levels (TRLs) are measures used to assess the maturity of evolving technologies (devices, materials, components, software, work processes, etc.) during its development and in some cases during early operations. Generally speaking, when a new technology is first invented or conceptualized, it is not suitable for immediate application. Instead, new technologies are usually subjected to experimentation, refinement, and increasingly realistic testing. Once the technology is sufficiently proven, it can be incorporated into a system/subsystem. Definitions[edit] Different definitions are used. U.S. Related DoD definitions[edit] The DoD uses similar definitions for the following specialized areas: Software Technology Readiness Levels[2]Biomedical Technology Readiness LevelsManufacturing Readiness Level NASA definitions[edit] ESA definition[edit] If the TRL is too low, then a mission risks being jeopardized by delays or cost over-runs.
Online[edit] Department of Defense Architecture Framework. DoD Architecture Framework v1.5.[1] DoDAF Architecture Framework Version 2.0[2] This Architecture Framework is especially suited to large systems with complex integration and interoperability challenges, and it is apparently unique in its employment of "operational views". These views offer overview and details aimed to specific stakeholders within their domain and in interaction with other domains in which the system will operate.[3] Overview[edit] The DoDAF provides a foundational framework for developing and representing architecture descriptions that ensure a common denominator for understanding, comparing, and integrating architectures across organizational, joint, and multinational boundaries.
It establishes data element definitions, rules, and relationships and a baseline set of products for consistent development of systems, integrated, or federated architectures. All major U.S. History[edit] Evolution of the DoDAF since the 1990s. Capabilities and Mission[edit] DoD C4ISR Framework. COSYSMO. The Constructive Systems Engineering Cost Model (COSYSMO) was created by Ricardo Valerdi while at the University of Southern California Center for Software Engineering.
It gives an estimate of the number of person-months it will take to staff systems engineering resources on hardware and software projects. Initially developed in 2002, the model now contains a calibration data set of more than 50 projects provided by major aerospace and defense companies such as Raytheon, Northrop Grumman, Lockheed Martin, SAIC, General Dynamics, and BAE Systems.
Similar to its predecessor COCOMO, COSYSMO computes effort (and cost) as a function of system functional size and adjusts it based on a number of environmental factors related to systems engineering. COSYSMO's central cost estimating relationship, or CER is of the form: where "Size" is one of four size additive size drivers, and EM represents one of fourteen multiplicative effort multipliers. See also[edit] Further reading[edit] External links[edit]