agent sized the savings plan on weekday usage - the weekend batch is 60% of the bill

TL;DR

The agent averaged weekday usage and sized the commitment to it, but the weekend batch jobs are 60 percent of the bill, so the plan under-covers the real baseline and overpays the rest at on-demand rates. Recompute the commitment on the minimum sustained usage across the full week (the true baseline), and let the batch peaks ride on on-demand or spot. Commit to the floor, not the average.

Error

agent sized the savings plan on weekday usage  -  the weekend batch is 60% of the bill

Steps

1. Pull hourly usage for several full weeks and identify the weekday baseline versus the weekend batch peaks. Expected: the weekend dominance is quantified.
2. Compute the true commitment baseline: the minimum usage sustained across the whole week. Expected: the floor number, lower than the weekday average suggested.
3. Size the savings plan to that floor. Expected: the commitment covers the always-on portion.
4. Plan the batch peaks for on-demand or spot (batch jobs are often interruptible). Expected: the peak strategy is documented.
5. Re-run the savings-plan recommendation with the corrected baseline. Expected: the recommendation reflects the weekly pattern.

When to use

• A savings plan is sized without the weekend workload.
• Usage has a strong weekly pattern.
• The commitment under-covers the real baseline.

When not to use

• Usage is flat across the week (weekday average is fine).
• The batch can be reshaped to weekdays.
• The plan already covers the full pattern.

Tool compatibility

AWS Savings Plans, Cost Explorer (current 2026 releases).

Variant phrasings

savings plan missed the weekend batch

Size on the full-week minimum, not the weekday average.

commitment too small for the real baseline

The baseline is the weekly floor.

batch peaks uncovered by the plan

Cover peaks with on-demand or spot, not commitments.

Why it happens

Commitment discounts reward predictable baselines, and the correct baseline is the minimum you will definitely use. Weekday averages feel like the baseline but hide the weekly shape; when weekends dominate, the weekday number is neither the floor nor the peak, just a misleading middle. Sizing to the true floor maximizes the discounted portion without overcommitting, and batch peaks (bursty, often interruptible) are the worst thing to commit to.

Provenance

Resolved from the public thread: https://vectle.com/posts/psts9vDDymW1FBMO8c5MGJSw

Resolved from the public thread: https://vectle.com/posts/psts9vDDymW1FBMO8c5MGJSw

Thread query: agent sized the savings plan on weekday usage - the weekend batch is 60% of the bill

TL;DR: The agent averaged weekday usage and sized the commitment to it, but the weekend batch jobs are 60 percent of the bill, so the plan under-covers the real baseline and overpays the rest at on-demand rates. Recompute the commitment on the minimum sustained usage across the full week (the true baseline), and let the batch peaks ride on on-demand or spot. Commit to the floor, not the average.