INCOSE Needs and Requirements Manual
ISBN: 978-1-394-15276-6 | October 2024 | 528 pages
Authors
Lou Wheatcraft, Wheatland Consulting, LLC, USA
Mike Ryan, Capability Associates Pty Ltd, Australia
Tami Katz, BAE Systems, USA
International Council on Systems Engineering
Purpose
The INCOSE Needs and Requirements Manual (NRM) presents systems engineering (SE) from the perspective of the definition and management across the system lifecycle of needs, requirements, verification, and validation (NRVV). NRVV are common threads that tie together all lifecycle activities and processes.
As presented in the Manual, for acceptance, certification, and qualification, the system or product being developed is verified against design input requirements and validated against its integrated set of needs. To successfully complete system verification and system validation, the needs and requirements of the system as well as the system verification and validation artifacts must be managed throughout the entire system lifecycle. The Manual provides practical guidance on the concepts and activities required to achieve those outcomes.
As shown in Figure 1, the NRM supplements and elaborates the INCOSE Systems Engineering Handbook (INCOSE SE HB) and the Systems Engineering Body of Knowledge (SEBoK) as well as standards such as ISO/IEC/IEEE 15288 and ISO/IEC/IEEE 29148, providing more detailed guidance on the “what’, “how’, and “why” concerning NRVV across the system lifecycle. The NRM also addresses ambiguity and inconsistencies in NRVV terminology and ontology.
Figure 1: Relationships Among RWG Products
The underlining concepts and activities within the NRM are supported by the related INCOSE guides: the Guide to Writing Requirements (GtWR), the Guide to Needs and Requirements (GtNR), the Guide to Verification and Validation (GtVV), and domain-specific guides such as the Guide to Security Needs and Requirements. Additional information is provided in the RWG Whitepaper Integrated Data as a Foundation of Systems Engineering. The GtWR is also supported by a useful Summary Sheet.
Scope
To support PM and SE from an NRVV perspective, the NRM:
Provides PM and SE practitioners with an understanding of the best practices for effective NRVV definition and management throughout the system lifecycle.
Helps organizations understand that NRVV are key elements of SE activities.
Provides guidance to the successful implementation of NRVV activities as part of PM and SE, in any domain.
Reinforces the idea that adequate definition of lifecycle concepts and a well-formed set of needs is a prerequisite to the definition of a well-formed set of system design input requirements.
Provides practical, cross-domain guidance to enable organizations to integrate best practices and concepts within their PM and SE processes, activities, WIs, and procedures.
Provides a clear description of how the terms verification and validation are applied to the artifacts generated across the system lifecycle.
Describes the importance of planning early for verification and validation activities across the lifecycle and the inclusion of verification and validation artifacts in system models.
Provides thorough guidance to readers on planning, definition, execution, and reporting of verification and validation activities across the system lifecycle.
Provides guidance and best practices that will help customer’s avoid accumulating technical debt and enable projects and suppliers to deliver a winning product.
Presents a data-centric approach to NRVV definition and management.
Provides guidance for organization and enterprise-wide sharing of data and information associated with developing and managing an integrated set of needs, the resulting design input requirements and design output specifications, as well as verification and validation artifacts throughout the system lifecycle.
Supplementary Material
You may be interested in this other supplementary material :
Return to the Requirements Writing Course
Related Systems Engineering Books
You may be interested in the following related books:
R. Faulconbridge and M. Ryan, Applied Systems Engineering, 2nd ed, Artech House, 2026.
R. Faulconbridge and M. Ryan, Managing Complex Technical Projects, 2nd ed, Artech House, 2026.
M. Ryan, Requirements Practice in Conceptual Design, 2nd ed, Artech House, 2026.
edVirtus Systems Engineering Courses
If you are specifically interested in requirements writing, you may be interested in the edVirtus course:
You may be interested in the related courses:
Three-day Systems Engineering—Introduction.
Five-day Systems Engineering—Advanced.
Return to the Requirements Writing Course