How to Read a CPM Schedule Health Score

Product managers and schedulers often ask the same first question after an API call: “Is 72 good?” The honest answer is: it depends what failed inside the score. A composite health score is a triage instrument built on Critical Path Method (CPM) mathematics and industry health metrics—not a forecast of contractual completion.

This article walks through the Bellator health score response so you can brief stakeholders without overselling the number.

What the score is (and is not)

It is	It is not
A 0–100 composite of structural and CPM diagnostics	A Monte Carlo P50/P80 finish date
Aligned to DCMA / GAO / AACE concepts used in health metrics	A substitute for full PAM 200.1 checklist reporting
Deterministic for the same input schedule	A judgment on team performance or earned value alone

Bellator computes health via POST /api/v1/health/score. See the quickstart for the minimum payload.

Anatomy of the response

A typical successful response includes:

• score — 0 to 100 composite
• grade — letter band derived from the score
• breakdown — weighted component scores (for example float erosion, criticality, structural integrity)
• top_signals / findings — human-readable reasons the score moved
• recommendations — prioritized next actions
• metadata — task count, timing, API version

Grade bands (default mapping)

Grade	Score range	How to talk about it
A	≥ 90	Structurally strong; monitor execution
B	≥ 80	Good with localized issues
C	≥ 70	Usable but needs cleanup before formal review
D	≥ 60	Material network or float problems
F	< 60	Not review-ready; fix logic/structure first

Treat bands as communication aids. Contracts may impose stricter gates (for example “no open ends” regardless of score).

Worked example: same score, different stories

Imagine two schedules both scoring 74 (C):

Schedule	Dominant breakdown weakness	First fix
Alpha	Float erosion high; many near-critical tasks	Protect remaining float; reduce soft constraints
Beta	Structural integrity low; dangling activities	Close open ends; repair missing successors

If you only report “74,” leadership cannot choose a fix. Always pair the number with one sentence from top signals.

Example narrative:

Health score 74 (C). Primary drag is float erosion on the design–procure chain; three open ends remain in commissioning. Recommend closing open ends this week, then re-score before the DCMA package.

Reading the breakdown like a scheduler

Exact component names can evolve with the API version; the reading method stays stable:

1. Sort components ascending — worst first.
2. Map each weak component to a physical schedule action (add logic, split long tasks, remove hard constraints, refresh baseline).
3. Re-run CPM mentally: does the critical path still make sense to a superintendent?
4. Only then escalate to DCMA 14-Point or delay forensics.

Float erosion

Float erosion asks whether total float is thin across too much of the network. High critical-path density with little float means any slip becomes a finish slip.

Criticality / critical path density

A schedule where “everything is critical” is usually a modeling problem (missing calendars, constraints, or level-of-effort pollution)—not heroic urgency.

Structural integrity

Missing predecessors/successors, circular logic, or invalid dates destroy trust in every downstream metric. Fix structure before arguing BEI or CPLI.

Minimal API example

curl -X POST "https://api.bellatorsi.com/api/v1/health/score" \
  -H "Content-Type: application/json" \
  -H "x-api-key: YOUR_API_KEY" \
  -d '{
    "tasks": [
      {"id": "T1", "duration_days": 5, "predecessors": []},
      {"id": "T2", "duration_days": 10, "predecessors": ["T1"]},
      {"id": "T3", "duration_days": 5, "predecessors": ["T2"]}
    ]
  }'

For richer diagnostics, include planned dates, baselines, and task_type so LOE/summary/hammock tasks are excluded from topology statistics automatically.

How health score relates to other Bellator numbers

Signal	Best use
Health score	Fast triage, product UX, CI on pull requests of schedule JSON
DCMA 14-Point	Formal checklist / surveillance package
Schedule Risk Index (SRI)	Pre-simulation risk posture (deterministic)
Delay analysis (AACE 29R-03)	Attribution after variance exists

See also: What is DCMA 14-Point? and Schedule Risk Index: what the numbers mean.

Stakeholder one-pager template

Copy/paste for status emails:

Schedule health: {score}/100 ({grade})
Tasks analyzed: {n}
Top signals:
  1. ...
  2. ...
  3. ...
Actions this week:
  - ...
Re-score after: {date or milestone}

Next steps

• From health score to DCMA in one integration
• Playground — run sample schedules without wiring production keys
• API reference — health score

Sources

• DCMA PAM 200.1 schedule assessment concepts (critical path, float, baseline execution)
• GAO Schedule Assessment Guide — maintain a valid critical path
• AACE recommended practices on schedule health metrics (e.g. RP 92R-19 family)
• Bellator standards documentation