Research tools for design margins

MARVIN

Research tools for analysing design margins in complex engineered systems

Three integrated modules — parametric margin valuation, top-down margin allocation, and probabilistic margin risk — built around the Margin Value Method.

Module 2 · MARVIN

Margin Deployment Cascading

A step-by-step walkthrough of building and using a margin cascade.

Tutorial in preparation The structure below is final, but screenshots, example matrix data, and walk-through figures will be added as the module's documentation is completed.

Before you start

This tutorial walks through a full cascade on a simple worked example: a small consumer product whose stakeholder needs are translated into requirements, then into architectural element targets, then into design parameter margins.

You only need a modern web browser. The module runs entirely client-side; no installation is required.

Walkthrough

01

List stakeholder needs

Open the cascade tool and add the stakeholder needs at the top level. Each need carries an importance weight reflecting its relative priority — gathered from interviews, surveys, or domain expertise.

Screenshot: stakeholder needs panel
02

Build the first matrix: needs → requirements

Add the system requirements that, taken together, satisfy the stakeholder needs. Fill in the relationship cells — strong, medium, weak, or none — between each need and each requirement. The module rolls up the importance weights to give a prioritised list of requirements at the bottom edge of the matrix.

Screenshot: needs → requirements matrix
03

Cascade to the architecture matrix

The prioritised requirements automatically become the inputs of the next matrix. Add the architectural elements (subsystems, functional blocks) and fill in the relationship cells. The module produces weighted target margins at architectural level.

Screenshot: requirements → architecture matrix
04

Cascade to design parameters

Repeat the cascade one more level: each architectural target is decomposed into the design parameters that engineers will set. The module's output is a list of target margins on every design parameter, with a clear chain of justification back to a stakeholder need.

Screenshot: architecture → design parameters matrix
05

Read the Sankey overview

Switch to the Sankey view to see the entire cascade as a flow diagram. Hover over any design parameter to see exactly which requirements and stakeholder needs drove its target margin.

Screenshot: Sankey overview
06

Iterate

Edit any cell at any level. Changes propagate forward through the cascade automatically, so you can test the effect of re-prioritising needs or restructuring the architecture without re-doing the matrices manually.

Next steps