SCMON / UPL / SUSG
What you'll learn
UPL = kernel procedure logging (often on); SCMON = newer ABAP-side object usage (default off); SUSG = landscape aggregation — turn SCMON on 1–3 months before deciding to decommission.
- UPL: kernel-level procedure logging (form/method calls), often on by default.
- SCMON: newer, ABAP-side, records object usage (programs, FMs, classes), default off.
- SUSG: aggregates usage across systems for a landscape-wide view.
Three usage-logging tools are easy to confuse, yet picking the wrong one — or misreading what it captures — derails a decommissioning decision. UPL (Usage Procedure Logging) is the oldest: it works at the kernel level, recording procedure-level calls such as form and method invocations, and it is frequently switched on by default in many systems, so historic data may already exist. Because it is kernel-side it is low-overhead and broad.
SCMON is the newer, ABAP-side facility, and it is configured per system and is off by default. Rather than procedure granularity it records object usage — which programs, function modules, and classes are actually executed — which is exactly the lens you want when deciding whether a custom object is dead. SUSG is the aggregation layer: it rolls up usage across systems so you can reason about a whole landscape rather than one box, combining the per-system signals into a single picture.
The operational rule a senior internalises is timing: turn SCMON on one to three months before any decommission decision, on the productive system, so you capture a representative window including period-end and seasonal jobs. Switch it on the week before and you will 'discover' that the quarter-close report is unused — and delete something you very much needed. The tool is only as good as the observation window you give it.
Key points
- UPL: kernel-level procedure logging (form/method calls), often on by default.
- SCMON: newer, ABAP-side, records object usage (programs, FMs, classes), default off.
- SUSG: aggregates usage across systems for a landscape-wide view.
- Turn SCMON on 1–3 months before a decommission decision to capture a representative window.
- Too short a window misses period-end/seasonal jobs and risks deleting needed code.
Examples
Before retiring custom reports, switch SCMON on in production for a full quarter so month-end and quarter-close runs are captured, then use SUSG to confirm the objects are unused across every system in the landscape.
Source notes: clean-core-curriculum §9.3
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Build a prompt from this lesson + your question and open a fresh Claude chat with it pre-filled — handy for adapting a before/after pattern to your own object.