Designing a solution and BOM

From requirements to a defensible design, bill of materials, assumptions and proposal.

⏱ ~30 minModule 3 of 5Quiz ↓Common mistakes ↓

🎯 Learning objectives

Turn requirements into a traceable design
Build a complete, accurate bill of materials
Document assumptions, exclusions and risks

Make every line traceable

A good design lets anyone trace each device back to a requirement and each requirement forward to a device. Use a simple matrix: requirement → area → solution element → device(s) → verification method.

Design workflow

Requirements matrixFrom your discovery summary; confirmed by the customer.
Device placementDoors and cameras on floor plans, with camera FOV and pixel density at each target (see the Video track).
InfrastructureControllers and interface boards per door count; switches, PoE budgets, UPS; cable runs within limits; power supplies and batteries.
Platform and licensingVMS/ACS servers and roles, storage sizing, client workstations, licences per camera/door/reader/feature, software maintenance.
IntegrationHR/AD/Entra, ClearID or other PIAM, fire alarm interface, intercom, intrusion, elevators, visitor management.
ServicesInstallation, programming, commissioning, training, project management, documentation and support.
ReviewPeer review of design and BOM before it goes to the customer.

BOM checklist

Category	Often forgotten items
Access control	Door position switches, REX devices, power transfer hinges, power supplies and batteries, enclosures, EOL resistors, diodes, fire alarm relays, reader licences
Video	Mounts, adapters, junction boxes, poles, housings, SD cards for edge recording, IR illuminators, camera licences per sensor
Network	PoE budget, SFPs and fiber patch cords, UPS for switches, extra switch ports for growth
Servers	Storage overhead (RAID, free space), OS and SQL licences, failover servers, rack space
Software	Feature licences (e.g. federation, analytics, mobile), annual maintenance / support plans
Services	Programming, commissioning per door/camera, training, as-built documentation, permits and AHJ inspections

Assumptions, exclusions and risks

State them explicitly in the proposal. Examples: "Customer provides network switches with sufficient PoE budget per attached calculations", "Door hardware modifications by others", "Bitrates based on pilot measurements; storage sized for 30-day retention at those bitrates". This protects the customer, the integrator and you.

Presenting the design

One-page executive summary: problems, solution, outcomes, investment, timeline.
Design narrative by area with floor plans and camera views.
Appendix: calculations (PoE, bandwidth, storage), BOM, assumptions, exclusions, cybersecurity measures, compliance statements.

Common mistakes

Copy-pasting the last project's BOM.
Forgetting licences, maintenance and services.
No written assumptions or exclusions.
Designs that cannot be traced to requirements.
Ignoring code requirements until the AHJ inspection.

Check your understanding

1.Why keep a requirements traceability matrix?

So every device is justified by a requirement and every requirement is met by the design; it makes reviews, changes and value engineering much easier.

2.Name five commonly forgotten BOM items.

Power supplies and batteries, REX/DPS, power transfer hinges, mounts/adapters, SFPs, UPS, licences, maintenance, programming/commissioning services, SD cards.

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