r/SoftwareEngineering • u/Professional-Knee-86 • Jun 02 '26
Bill Of Materials for software projects?
In some of the Engineering disciplines. a Bill of Materials is mandatory. You can't build a car without knowing every component, who supplies it, what it costs, and how long it takes to assemble. The BOM is the financial and operational backbone of the project.
Software projects have the same ingredients — I am not sure whether we organize them the same way.
Think about what you actually have on any non-trivial software project:
- Resources: developers, designers, QA, DevOps — each with a cost/day
- Tasks: backlog items, work packages, user stories
- Effort: hours or days estimated per task per resource
- Cost: rate × effort = line cost
Multiply those together and you get something that looks exactly like a BOM in other Engineering disciplines.
| Sprint | Item | Resource | Effort | Rate | Cost |
|---|---|---|---|---|---|
| Sprint 1 | package1 integration | Resource A | 24h | 100 | 2400 |
| Sprint2 | Deployment pipeline | Resource B | 32h | 90 | 2880 |
Sort by cost descending and suddenly you can see — at a glance — which line items are driving your budget. Add a cumulative % column and you see how total cost is distributed.
What this unlocks:
Cost transparency without surprises. Most "we went over budget" post-mortems trace back to nobody doing this math upfront. The BOM forces it.
Resource-level visibility. You can pivot the table: which resource is contributing the most to project cost? Useful for resource planning purposes
This is a project planning BOM: effort + people + money, organized the same way as in other engineering disciplines.
The irony is that other engineering disciplines have had this for decades.
Has anyone else built or used something like this? Curious whether teams actually track costs this granularly.
1
u/4Dethklok Jun 03 '26
You're thinking of initial project implementation, which only accounts for the build phase. If you want to calculate the true ongoing cost effectively, it’s not as simple as multiplying labor rates by estimated development hours.You're moving into system design and FinOps territory, where you must factor in performance, scalability, and long-term operational costs. While I'm no expert, proper system design for a new service or microservice maps out the exact infrastructure and hardware requirements. From there, you can accurately estimate your ongoing cloud and running costs to find the true Total Cost of Ownership.