CASE STUDY
How Aceteroid Found an MSEG Performance Bottleneck in 6 Minutes
A hidden LOOP-based aggregation issue that could take around 8 hours to diagnose manually was identified and moved toward a database-side refactoring direction using SQL GROUP BY and HANA pushdown.
The original ABAPer feedback describes the object as a custom MSEG consumption analysis report that fetched material movement data, aggregated quantities and values, computed plant-level contribution percentages, and displayed results through ALV. The same feedback records the manual effort as 8 hours, Aceteroid-assisted output as 6 minutes, and the main improvement as replacing LOOP aggregation with SQL GROUP BY using I_MaterialDocumentItem_2
The Enterprise Problem
Custom SAP reports often continue to work long after their internal processing model becomes outdated. That is what makes them risky.
In this case, the report was not failing. It still produced business output. But underneath, it carried hidden performance debt: repeated ABAP-level aggregation over high-volume material movement data.
For S/4HANA modernization teams, this type of issue usually appears late — during performance testing, cutover simulation, or post-go-live stabilization. By then, delivery teams are already under timeline pressure.
The risk
The report worked.The processing model did not scale.
That made this more than a code cleanup problem. It was a modernization risk inside a working business report.
The Task
A senior ABAP developer tested Aceteroid on a custom report used for **MSEG consumption analysis** in the MM / Inventory Management context.
The report was designed to:
- 1. Fetch material movement data.
- 2. Aggregate consumption quantities and values.
- 3. Calculate plant-level contribution percentages.
- 4. Display the result through ALV.
The objective was not new development. The objective was performance optimization.
The developer wanted to answer one practical question:
Where is the real bottleneck, and what is the safest first refactoring direction?
The original feedback notes that the program had high complexity because it worked on the large MSEG transactional table, involved multiple aggregation passes, used derived plant-share calculations, and was performance-sensitive due to data volume.
Why This Was Not a Simple Code Fix
The issue was not old ABAP syntax alone. The real problem was the processing model.
The report was doing too much calculation inside ABAP. For high-volume MSEG/material movement data, that creates unnecessary load at the application layer.
What made it non-trivial
1. Classic aggregation debt
The report relied on a LOOP + READ + MODIFY pattern. As data volume grows, repeated internal table search and update becomes expensive.
2. Multiple processing passes
The program did not calculate everything in one clean flow. It used separate passes for aggregation, total calculation, and percentage calculation.
3. Architecture decision complexity
The developer had to decide whether aggregation should remain in ABAP, move to the database, use CDS, or be parallelized.
The hard part
The hard part was not “optimizing code blindly.”
The hard part was choosing the right strategy:
- Keep aggregation in ABAP
- Push aggregation to SQL
- Use a CDS-based access path
- Or introduce parallel processing
A manual review would have required tracing the aggregation flow, identifying the bottleneck, evaluating pushdown, comparing CDS versus direct table access, and deciding whether parallelization was justified.
Estimated manual effort: ~8 hours
What Aceteroid Did

The developer tested Aceteroid in two stages.
Attempt 1: General Optimization
The first output produced the strongest result.
The shift Aceteroid suggested
- Replace LOOP aggregation with SQL GROUP BY.
- Use
I_MaterialDocumentItem_2as an S/4HANA-oriented data-source direction. - Push aggregation closer to the database.
- Reduce data transferred to the application server.
- Follow the S/4HANA / HANA pushdown principle.
The original feedback confirms these improvements: Aceteroid replaced LOOP aggregation with SQL GROUP BY, used I_MaterialDocumentItem_2, pushed aggregation to the database, reduced application-server data transfer, and followed the S/4HANA pushdown principle.
Why this mattered
Aceteroid did not make the program more complex.
It identified the simpler and stronger first move:
Push aggregation to the database before adding more ABAP processing.
That was the main value of the first output.
Attempt 2: Parallelization
he developer then explicitly asked Aceteroid to explore parallelization.
Aceteroid proposed a more advanced approach using:
-
SPTA_PARA_PROCESS_START_2 - Plant-based workload partitioning with
WERKS - Hashed tables for result merging,
- Parallel RFC callbacks,
- DB-level aggregation per task.
This was technically relevant, but it introduced delivery complexity.
What became complicated
- Callback forms had to be handled.
- Task coordination became harder.
- Result merging added validation effort.
- Parallel RFC behavior increased debugging complexity.
- Multiple code corrections were required.
The feedback says the parallelization path became harder to maintain, required multiple corrections, and needed explicit prompting.
The decision
Database aggregation was the stronger first optimization path.
Parallelization was useful to explore, but it was not the default answer. For enterprise modernization, that distinction matters. The best solution is not always the most advanced one. Often, it is the simplest controlled refactoring that removes the core bottleneck.
Before Aceteroid vs With Aceteroid
- Manual code inspection
- Bottleneck found through developer tracing
- Strategy chosen through manual review
- Senior time spent on discovery
- Guided optimization review
- Bottleneck identified in minutes
- Database-side aggregation suggested first
- Senior time redirected to validation
Aceteroid did not remove developer judgment. It moved developer effort from manual discovery to controlled validation.
What Worked Well
It identified LOOP-based aggregation as the core issue and suggested SQL GROUP BY instead of repeated internal table aggregation. It also recommended I_MaterialDocumentItem_2 as an S/4HANA-oriented data-source direction and moved the report toward HANA pushdown.
- Bottleneck identified quickly
- Aggregation strategy moved to SQL GROUP BY
- S/4HANA-oriented access direction suggested
- Application-layer processing reduced
- First useful optimization direction generated in approximately 6 minutes
The strongest result was not complex code generation.
The strongest result was technical clarity: Aceteroid found the real bottleneck and gave the developer a practical path forward.
What Still Needed Developer Review
The output was not treated as final production code.
A senior ABAP developer still needed to validate whether the suggested optimization preserved the original business result and fit the target system.
Validation still required
- Confirm whether the suggested CDS view and fields exist in the target landscape
- Compare old and new output for the same material and plant selections
- Validate quantity and value calculations
- Confirm plant contribution percentages
- Review ALV output
- Benchmark runtime behavior with realistic data volumes
- Decide whether parallelization is justified after database aggregation
The parallelization path needed extra caution because it introduced callback handling, task coordination, and result-merging logic.
This is the right enterprise model:
Aceteroid accelerates technical discovery and refactoring direction.
The ABAP developer retains control over correctness, performance validation, and production sign-off.

The Numbers
- Initial optimization analysis
- Bottleneck Identification
- Refactoring Direction
- S/4HANA data-source review
- ~8 hours
- Manual tracing required
- Manual strategy review
- Manual Evaluation
- ~6 minutes
- Identified in first output
- SQL GROUP BY direction suggested
-
I_MaterialDocumentItem_2suggested
Honest Claim
Aceteroid reduced the time required to identify the bottleneck and produce an initial database-side refactoring direction from approximately 8 hours to 6 minutes.
This does not claim that the report was production-benchmarked, deployed, or fully signed off in 6 minutes.
It claims something more credible:
The developer reached the right optimization path significantly faster.
Output Quality Assessment
The ABAPer rated the overall output as Good. The database aggregation output was strong because it addressed the actual performance issue. The pushdown recommendation aligned with S/4HANA performance principles.
The parallelization output was useful as an exploration, but not as a final answer. It required explicit prompting, introduced more complexity, and needed multiple corrections.
Quality verdict
Strong: database aggregation direction
Useful but complex: parallelization exploration
Still required: Senior ABAP validation
That distinction makes the case study more credible.
Aceteroid handled the core bottleneck well. The more complex parallelization path still required senior ABAP judgment.
Why This Matters for S/4HANA Modernization
S/4HANA modernization is not only about making old ABAP code run. It is about identifying which custom objects need to change, why they need to change, and how to modernize them without creating unnecessary risk.
In this case, the report worked functionally, but the processing model created performance risk. It used repeated ABAP-level aggregation over high-volume material movement data.
That type of issue may not appear as an immediate functional defect, but it can slow down testing, cutover simulation, and post-go-live stabilization.
- Manual code inspection became guided optimization review
- Bottleneck discovery became faster
- Database-side aggregation became the first refactoring direction
- Senior ABAP time moved from repetitive tracing to validation
For one report, the result was faster optimization analysis. Across a custom ABAP portfolio, the value is larger.
Enterprise SAP teams often have hundreds of custom reports with similar patterns: SELECT-heavy processing, LOOP-based aggregation, repeated internal table passes, derived calculations, and ALV-heavy output structures.
The modernization value is earlier clarity, safer refactoring direction, and controlled developer validation.
Why This Matters for Enterprise SAP Teams
Enterprise SAP landscapes usually contain many custom reports built over years of business-specific requirements. Some are small, some are critical, and some are rarely reviewed until migration pressure exposes them.
The common challenge is not only code volume. It is decision volume.
- 1. Should it stay as-is?
- 2. Should it be optimized?
- 3. Should it be rewritten?
- 4. Should it be retired?
- 5. Should it use a more complex architecture such as parallelization?
This case shows Aceteroid helping with one of those decisions.
It did not simply generate code. It clarified which optimization path made sense first.
For delivery teams, that matters because modernization programs need more than speed. They need controlled decisions that developers can validate and explain.
Impact Summary
Aceteroid’s impact in this case was not just faster output generation. It changed how the developer approached the performance problem.
- Manual effort estimate
- Aceteroid-assisted output
- Time saved
- Effort reduction
- Main technical shift
- Developer role shift
- ~8 hours
- ~6 minutes
- ~7.9 hours
- ~98% for initial optimization analysis
- ABAP-level aggregation → database-side aggregation
- Manual tracing → validation and sign-off
The time saving comes directly from the ABAPer’s recorded numbers: 8 hours manually, 6 minutes with Aceteroid, and 7.9 hours saved.
What changed in practice
- 8-hour manual review estimate
- Bottleneck discovery through manual tracing
- Optimization strategy chosen through developer trial and review
- Senior ABAP time spent on repetitive analysis
- 6-minute optimization direction
- LOOP aggregation bottleneck identified quickly
- SQL GROUP BY / pushdown-first approach suggested
- Senior ABAP time redirected to validation
The time saving comes directly from the ABAPer’s recorded numbers: 8 hours manually, 6 minutes with Aceteroid, and 7.9 hours saved.
Enterprise meaning
For a single report, Aceteroid saved almost a full working day of initial performance review.
Across a custom ABAP portfolio, the same pattern can compound. If many reports contain similar LOOP-based aggregation, SELECT-heavy logic, or repeated internal table processing, Aceteroid can help teams identify modernization candidates earlier and reduce senior-developer time spent on repetitive discovery.
The impact is not only speed. It is earlier clarity, better refactoring direction, and more senior ABAP capacity for validation.
Practitioner Response
Aceteroid quickly identified that the real issue was the aggregation model. The report was doing too much processing inside ABAP. The database aggregation output was useful within minutes. Parallelization still needed review, but the main optimization direction became clear very quickly.
Senior ABAP Developer
SAP Engineering Team, ERPROOTS
Key Takeaway
Aceteroid worked best as a performance-debt discovery and guided refactoring accelerator.
It helped identify a high-risk ABAP aggregation pattern, moved the solution toward database-side processing, and gave the developer a clear optimization direction in minutes.
The final model
- Bottleneck Discovery
- Refactoring Direction
- Pushdown Recommendation
- Optimization Path Comparison
- Business Correctness
- Data-source validation
- Runtime benchmarking
- Production sign-off
Aceteroid speeds up repetitive technical discovery. Senior ABAP developers retain control over the decisions that matter.
What This Case Proves
1. Technical depth
You receive the Eclipse plugin, a license key, and 30 free credits to explore Aceteroid.
2. S/4HANA modernization direction
Credits are deducted from the same wallet balance based on the feature used and task complexity.
3. Speed to clarity
You can view used credits, remaining balance, and feature-wise usage inside the tool/platform.
It also proves the boundary: parallelization was explored, but not treated as the default answer. Final validation remained with the ABAP developer.
Aceteroid produced the first database-side refactoring direction in 6 minutes for an MSEG report that was estimated to take 8 hours of manual performance review.

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