MARVIN tools
Module 02

Margin Deployment Cascading

Allocate margins top-down, from stakeholder needs through requirements and architecture down to design parameters, using a chain of QFD-inspired matrices.

Overview Organisation Tutorial Case Studies Literature
01

Overview

Margins are usually decided locally at design parameter level ? an extra millimetre of clearance, a slightly larger pump, an additional safety factor. The reason for those margins lives further up: a stakeholder need, a requirement, or an architectural choice. Margin Deployment Cascading makes that vertical link explicit.

The module borrows the cascading idea from Quality Function Deployment (QFD): the outputs of one matrix become the inputs of the next, so allocations made at one level of abstraction propagate and refine at the level below. Margins follow the same chain.

02

The cascade

3

Each matrix relates two levels of abstraction. The prioritised items on its bottom edge become the input of the next matrix.

Level 01
Needs to requirements

Translate stakeholder needs into measurable system requirements, with weights that reflect relative importance.

Level 02
Requirements to architecture

Map weighted requirements onto architectural elements, subsystems, or functional blocks that contribute to satisfying them.

Level 03
Architecture to parameters

Decompose architectural allocations into the design parameters engineers set, producing target margins for each parameter.

03

What the module supports

Feature
Linked matrices

Edits at one level update the next so the cascade stays consistent without copy-paste between sheets.

Feature
Margin allocation

Relationship weights roll up to target margins on requirements, architecture elements, and design parameters.

Feature
House-of-quality view

Relationship matrices can be read in classic QFD form, including correlations where useful.

Feature
Traceable rationale

The resulting allocations keep a visible line back to the stakeholder needs that motivated them.

04

Where to go next