Introduction

1. Revision history: one sentence update on what this revision changes from previous revisions
2. Introduction: brief description of what this subsystem is / is doing
3. Purpose: why does this subsystem need to exist
4. Scope: what is in this document

The Design

Requirements

1. Core Functionality: what this system does
2. Performance Metrics: how can the design be evaluated AND target performance

Research

1. Alternative Enumeration: how is this done today?
2. Alternative Analysis: what are the pros+cons of these methods

Key Assumptions

Design Details (selected design)

1. Description: pictures, sketches, block diagram, CAD, algorithm, …
2. Interfaces: what data/resources enter and exit this system
3. Performance Analysis: estimation of performance metrics (math preferred)
4. Risk & Mitigation: how can this design fail & backup plans (redundancy + what is hard?)