Requirements development is a process that consists of a set of activities that produce requirements for a product. The systems engineering standard [EIA 632] defines “requirement” as “something that governs what, how well, and under what conditions a product will achieve a given purpose.” Requirements define the functions, performance, and environment of the system under development to a level that can be built:

• Does the system do WHAT it is supposed to do? – These are Functional Requirements
• How well does the system do its functions? – These are Performance Requirements

In the Department of Defense (DoD) the requirements process is governed by the Joint Capabilities Integration and Development System (JCIDS) Process. The JCIDS Process ensures the capabilities required by the DoD are identified and their functional and performance requirements are developed. The main engineering disciple that develops and controls requirements development is Systems Engineering (SE). Requirements development is Step One: Requirements Analysis of the Systems Engineering Process. The four (4) main requirements documents that are produced on a typical DoD program during a specific Acquisition Phase are:

• Initial Capabilities Document (ICD)
• Capability Development Document (CDD)
• System Requirements Document (SRD)
• Weapons System Specification (WSS)

Requirements Development Steps

There is no set standard way to develop requirements but they are normally developed following the same basic six (6) steps. These requirements development steps don’t really change depending on which SE model is used. All models are similar in their approach but they just usually depict the step differently graphically. The main model that is used is the Systems Engineering “Vee” where requirements development is depicted on the left side.

Below is a list of the basic six (6) steps of requirements development.

• Overview: Requirements Development Steps
• Step 1: Gather and Develop Requirements
• Step 2: Write and Document Requirements
• Step 3: Check Completeness
• Step 4: Analyze, Refine, and Decompose Requirements
• Step 5: Verify & Validate Requirements
• Step 6: Manage Requirements

Other Requirements Development Topics

Other topics that Stakeholders, Program Managers (PM), and Systems Engineers need to know about Requirements Development are:

• Requirements Tracing
• Capability Development Tracking and Management (CDTMM) Tool
• Feasibility Assessment
• Requirements Checklist
• Joint Capability Area Attributes
• Joint Service Specifications Guides (JSSG)
• Standardization
• Requirement Types
• Requirements Allocations
• Requirements Development Sequence
• Requirements Evaluation

AcqLinks and References:

• Defense Acquisition Guidebook (DAG)
• DAU Systems Engineering Fundamentals Guide
• Space and Missile Systems Center (SMC) Systems Engineering Primer & Handbook
• Writing a Requirements Document “For Multimedia and Software Projects” by Rachel S. Smith
• NASA Systems Engineering Handbook (large 9 Mb file)
• EIA-632 “Processes for Engineering a System” – 7 Jan 99
• Requirements Development Checklist
• Presentation: Processes for Engineering a System EIA – 632

Updated: 8/18/2022

Rank: G1