This is a ready-to-use ledger for the one thing many excursion systems quietly get wrong: tracking the cumulative thermal budget of a lot across its whole distribution life. Excursion allowances are cumulative, not per-event. A lot that used 12 of its 24 permitted hours above 8 C on one leg has 12 left, and that has to carry forward or the next disposition is made blind. This ledger is the running record that carries it. Replace every <<FILL: ...>> placeholder. A filled specimen follows.
Purpose
To maintain, per lot, a running total of temperature excursion time (and other budgeted conditions) spent against the product’s registered stability allowances, so that every disposition is made against the remaining budget rather than assessing each excursion in isolation.
When to use
Open one ledger per lot when it is released for distribution. Update it at every recorded excursion, on every leg (warehouse, transit, final mile, returns). The disposition authority (Quality / Responsible Person) references it for every excursion decision.
Lot header
| Field | Entry |
|---|---|
| Product / lot number | <<FILL>> |
| Labeled storage condition | <<FILL: e.g. 2-8 C>> |
| Registered warm-side allowance | <<FILL: e.g. 48 h cumulative between 8 C and 25 C>> |
| Registered cold-side allowance | <<FILL: e.g. 0 h below 0 C (no freeze budget)>> |
| Other budgeted limits | <<FILL: e.g. above 25 C: 0 h; light: N/A>> |
| Ledger owner | <<FILL: role>> |
Field definitions
| Field | Format | Required | Who | When |
|---|---|---|---|---|
| Date | Date | Yes | Ops / Quality | At each event |
| Leg | Text (warehouse / transit / final mile / return) | Yes | Ops | At each event |
| Event | Text | Yes | Ops | At each event |
| Excursion detail | Peak temp + duration | Yes | Ops | From logger data |
| Direction | Warm / Cold | Yes | Quality | At each event |
| Budget used this event | Hours (to the correct budget) | Yes | Quality | At each event |
| Cumulative used | Running total per budget | Yes | Quality | At each event |
| Remaining | Allowance minus cumulative | Yes | Quality | At each event |
| MKT over period | C | If applicable | Quality | At each event |
| Disposition | Continue / Reject / Hold | Yes | Quality / RP | At each event |
| Signed / date | Signature + date | Yes | Quality / RP | At each event |
The ledger
| Date | Leg | Event | Excursion detail | Direction | Used this event | Cumulative used | Remaining | MKT | Disposition | Signed / date |
|---|---|---|---|---|---|---|---|---|---|---|
<<FILL>> | <<FILL>> | <<FILL>> | <<FILL>> | <<FILL>> | <<FILL>> | <<FILL>> | <<FILL>> | <<FILL>> | <<FILL>> | <<FILL>> |
Instructions
- Charge each excursion to the correct budget by direction. Warm-side time and cold-side time are separate budgets; a freeze is never offset by unused warm-side hours.
- Compute duration from the full logger trace, not a single reading, and record peak plus duration.
- Where the product file requires it, compute MKT over the affected period (Arrhenius-weighted, using the product’s activation energy or the default in the product file), and never disposition on the arithmetic average.
- Carry the cumulative total and remaining forward to the next leg. A new leg starts from the remaining, not from zero.
- If any budget reaches zero, or an excursion occurs in a direction with no budget (for example any freeze on a do-not-freeze product), the default disposition is Reject regardless of remaining budget in the other direction.
- Quality or the Responsible Person signs each disposition; the ledger travels with the lot record.
Acceptance criteria
- Every recorded excursion is charged to the correct directional budget with peak and duration.
- The cumulative and remaining totals carry forward across all legs.
- No freeze excursion is offset against warm-side budget.
- Every disposition is signed by the authorized decision-maker and shows the math, not just the conclusion.
Filled specimen
Illustrative ledger for a 2-8 C biologic with a registered allowance of 48 cumulative hours between 8 C and 25 C and zero allowance below 0 C.
| Date | Leg | Event | Excursion detail | Direction | Used this event | Cumulative used | Remaining | Disposition |
|---|---|---|---|---|---|---|---|---|
| 02 Jun | Warehouse | Dock-door spike | 11 C, 35 min | Warm | 0.6 h | 0.6 h | 47.4 h | Continue |
| 05 Jun | Air transit | Tarmac hold | 19 C, 5 h | Warm | 5.0 h | 5.6 h | 42.4 h | Continue |
| 07 Jun | Final mile | Reefer fault | 14 C, 3 h | Warm | 3.0 h | 8.6 h | 39.4 h | Continue |
After three events the lot has spent 8.6 of 48 warm-side hours and never went below 0 C, so it is released for continued distribution with the budget carried on the lot history and the tarmac-hold cause trended for CAPA. Now change one fact: if the final-mile reefer had dropped to -3 C for 20 minutes, there is no cold-side budget, so the disposition flips to Reject regardless of the 39.4 warm-side hours remaining. The freeze, not the heat, decides.
Common findings this ledger prevents
- Each excursion assessed in isolation, so the cumulative thermal history is lost and a lot near its budget is released as if fresh.
- A freeze excursion given credit against unused warm-side budget.
- Disposition on an arithmetic average instead of duration and MKT.
- A “within stability” release with no calculation showing the specific cumulative exposure.
How to adapt this ledger
- Set the exact registered allowances for the product, by direction, from the stability file.
- Add columns for any other budgeted condition the product carries (time above 25 C, light exposure).
- Keep it on the lot record as a running ledger, on paper or in a validated system, so it travels with the lot.
- Feed recurring excursion causes into corrective and preventive action and connect the disposition to your excursion management SOP.