Chapter 1 — Foundations

This chapter explains how to use the workbook, the sequence of the nine design steps, and why each calculation is mandatory before any AI workload is introduced to enterprise infrastructure.

In this chapter

• How to Use This Workbook — Design gate methodology, step sequence, and when to run each calculation
• Formula Overview — All formulas on one page with variable definitions and enterprise adaptations

The design gate principle

Every formula in this workbook is a gate, not a guideline. If the IS gate fails (IS > 10), no further AI deployment proceeds until infrastructure is corrected. This is not a recommendation — it is a hard project risk boundary.

Step 1: U_eff  →  Step 2: AIW  →  Step 3: CS  →  Step 4: LL
                                                        |
Step 9: Upgrade  ←  Step 8: MCP  ←  Step 7: PUO  ←  Step 5: B
                                                        |
                                                   Step 6: IS gate

Who should use this workbook

Role	Primary chapters
Network architect	All — primary user
WAN / SD-WAN engineer	Chapters 4, 7
Security engineer	Chapter 3 (CS scoring)
Contact centre architect	Chapters 2, 5, 6
AI/ML infrastructure engineer	Chapters 2, 4, 6
Project manager	Chapter 1, IS thresholds, Chapter 9