Schedule Logs
A schedule shows the state; the log explains the change. Schedule logs are the narrative and change records that travel with every submission — what moved between updates and why — so each one is transparent and defensible. Built on AACE 93R-17.
What a schedule log is
Logs are the connective tissue of the control loop. Statusing (Lesson 15) produces the update; the review (Lesson 16) checks it; the log is what makes that review possible — it tells the reviewer what to look at and why each change was made, instead of leaving them to diff thousands of activities by eye.
What gets logged
The change log captures every meaningful difference from the previous schedule. The categories to track:
- Added / deleted activities — New scope, rework activities, or removed work — with what and why.
- Logic changes — Added, removed, or revised relationships and lags — the changes most likely to shift the critical path, and most prone to abuse.
- Duration changes — Original durations or remaining durations revised — with the reason (re-estimate, scope change, productivity).
- Calendar & constraint changes — New calendars or, critically, any added/removed constraints — which can mask slippage.
- Progress & data date — The new data date and the actuals applied this period.
The narrative report
Alongside the change list sits the narrative — a short written report each period covering what actually happened, not just what changed in the file. A good narrative says: progress this period, current status vs baseline, the critical path and its movement, delays and their causes, recovery actions, and look-ahead concerns.
Logs and the long game
Schedule logs do their most valuable work long after they're written. When a dispute arises (Track 6), the question is always "what was planned, what changed, and why?" A disciplined series of logs answers it directly — a contemporaneous, period-by-period record of every change and its stated reason, made before anyone was thinking about a claim.
| Logs give you… | Which means… |
|---|---|
| A reviewable update | Faster, fairer acceptance each period |
| A record of why logic changed | No "unexplained manipulation" accusations later |
| A contemporaneous narrative | Strong evidence of cause and timing for claims |
Ten things to remember
- A schedule log records what changed and why between versions — facts plus reasons.
- Logs make the update review possible — they tell the reviewer what to look at.
- Log added/deleted activities, logic, durations, calendars, constraints, and the data date.
- Logic and constraint changes get the most scrutiny — they move the critical path invisibly.
- Pair the log with a narrative — the story of progress, status, delays, and recovery.
- The log records facts; the narrative interprets them.
- A complete log = nothing to hide — it's what gets an update accepted, not argued.
- Logs are contemporaneous evidence — the period-by-period record claims rely on.
- Issue logs with every submission — they travel with the schedule, not after it.
- Logs are cheap insurance — small discipline now, huge value in any dispute.
Glossary
- Change log
- The itemized list of differences from the prior schedule version.
- Constraint change
- An added/removed date constraint that can mask slippage.
- Contemporaneous record
- Documentation made at the time — the most credible evidence.
- Data date
- The cutoff for the update; recorded in the log.
- Logic change
- An added/removed/revised relationship — the highest-scrutiny change type.
- Narrative report
- The written account of progress, status, issues, and reasons.
- Schedule log
- The record of changes and narrative accompanying a schedule submission.
- Transparency
- The property of an update whose every change is documented and explainable.