Task: Allocate Requirements to Engineering Disciplines

This task takes the requirements allocated to a subsystem as a whole and allocates them to the different engineering disciplines inolved (e.g. software, electronics, mechanical, optical, hydraulic).

Purpose

The purpose is to clearly delinate the required contributions of different engineering disciplines to the engineering development of a subsystem by allocating the requirements allocated to the subsystem by the system engineering team.

Relationships

Roles	Primary: Control Engineer Developer Electrical Engineer Mechanical Engineer Miscellaneous Engineer	Additional: Architect Reliability Czar Safety Czar	Assisting:
Inputs	Mandatory: Requirements Traceability Subsystem Model Systems Requirements Specification	Optional: Failure Modes and Effect Analysis Fault-Tree Analysis Hazard Analysis	External: None
Outputs	Requirements Traceability Subsystem Requirements Specification

Main Description

A subsystem team is usually comprised of engineers within different disciplines, such as software, digital electronics, analog electronics, hydraulic, pneumatic, control, and mechanical. Once the subsystem specification is handed off, certain of the requirements will belong to one discipline or the other. Other requirements will require decomposition into derived requirements, allocating portions of a subsystem-level requirement to different discipline. This is particularly true of quality-of service requirements.

Steps

Review subsystem requirements

This step examines the subsystem specifications in all its forms - including SysML models, state and control specifications, requirements specifications, and logical and physical subsystem interfaces to make sure that the interdisciplinary team understands what is necessary. If requirementrs are missing, incomplete, inadequate, or incorrect, clarification from the system engineering team or subject matter experts must be sought.

Allocate single-discipline requirements

Many of the requirements will be clearly related to a single discipline. These may be allocated directly.

Decompose multi-discipline requirements

Many subsystem requirements require the interaction of one or more engineering disciplines. Clarity as to which responsibility will be met by which discipline is required. This is best done with a collaboration of the engineering staff from all relevant disciplines - such as electronics and software - to arrive at an optimal solution. This results in derived requirements. Derived requirements must together met the original subsystem requirement.

Allocate derived requirements

Each derived requirement should be allocated to a single subsytem engineering discipline. If a derived requirement cannot be allocated to a single subsystem, then it must be further refined.

Update traceability record

Depending on the level of traceability required, the traceability record for the requirements should be updated to show which engineering discipline within the subsystem has responsibility for meeting the allocated requirements.

Review allocations

This step constitutes a review of the requirements, their deivations, and their allocations with an eye towards coverage (all subsystem requirements must be allocated), completeness (identify any missing requirements), and achievability.