Cost and velocity deltas
Deltas show how a scenario differs from Live.
Use them to evaluate trade-offs before promotion.
What a delta means
A delta is the difference between:
- Scenario value (proposed state)
- Live value (current baseline)
Positive and negative deltas are not automatically good or bad. Interpretation depends on intent.
The summary compares the scenario's latest available aggregate snapshot with Live's latest available snapshot. If the scenario has a newer recompute than Live, the delta reflects that newer scenario total immediately. Archived scenarios stay pinned to their archive date so the comparison does not drift later.
Core delta lenses
Cost deltas
Use cost deltas to answer:
- What is the monthly increase or decrease?
- Which units drive most of the change?
- Is the change aligned with expected capacity gains?
Velocity deltas
Use velocity deltas to answer:
- Does delivery capacity improve in target areas?
- Are we trading speed in one area for gains in another?
- Is the velocity change plausible based on placement edits?
How to review deltas effectively
- Start with top-level totals.
- Drill into major contributors by team/department.
- Validate that structural edits explain the metric shift.
- Document assumptions before decision meetings.
Decision framing
Use a simple decision frame:
- Impact: What changes materially?
- Confidence: How reliable is this estimate?
- Trade-off: What did we gain and what did we accept?
This keeps reviews concrete and comparable across scenarios.
Common interpretation mistakes
- Treating small delta movement as noise without checking structural causes.
- Looking at cost without matching it to capacity/velocity shift.
- Comparing scenarios with different scope and calling one "better" by default.
Practical review template
- Scenario intent
- Top 3 cost changes
- Top 3 velocity changes
- Known assumptions
- Recommendation: promote, refine, or reject