marcellourbani/abap-code-writing

ABAP Code Writing Process

Follow this process in order whenever building ABAP solutions. Do NOT skip steps. Do NOT start writing code until Step 6.

Ask questions at ANY step if something is unclear — it is always better to clarify early than to rewrite later.

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Step 1: Understand the Requirement

Before anything else, demonstrate that you understand what the user is asking for.

Actions:

• Restate the requirement back to the user in your own words
• Describe the expected inputs, outputs, and behavior
• Identify the business context — what problem does this solve?
• Call out any assumptions you're making
• List open questions (edge cases, error scenarios, authorization needs, performance expectations)

Do NOT proceed until the user confirms your understanding is correct.

Example response:

"Here's my understanding: You need a report that reads material master data for a given plant, filters by material type, and outputs an ALV grid with columns [X, Y, Z]. It should support multiple selection for plant and material type. Is this correct? A few questions: (1) Should it include cross-plant materials? (2) Do you need export to Excel? (3) Any authorization checks beyond standard?"

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Step 2: Explore the SAP System

Once requirements are confirmed, understand what you're working with.

Actions:

• Use the SAP system info tool to determine:
  • System type (S/4HANA vs ECC)
  • SAP release / ABAP version (affects available syntax and standard objects)
  • Installed components
• Check if standard SAP functionality already does what the user needs:
  • Search for standard transactions, BAPIs, or reports that cover the requirement
  • Search for BADIs, enhancement spots, or user exits that could be enhanced
  • Check if a standard Fiori app exists for this
• Inform the user of findings: "SAP already provides [X] which does 80% of what you need. We could enhance it via [BADI/exit Y] rather than building from scratch."

If standard functionality can be enhanced, recommend that approach. Custom code should be the last resort.

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Step 3: Architecture & High-Level Plan

If custom development is needed, plan the architecture BEFORE any code.

Actions:

• Break down the solution into sub-tasks / capabilities needed. Examples:
  • Sending emails
  • Downloading data to Excel
  • Price calculation
  • Updating a specific custom table
  • Reading master data
  • Calling an external API
  • Authorization checks
  • Logging / audit trail
• For each sub-task, note whether it's likely something that:
  • Already exists as standard SAP functionality (BAPI, FM, standard class)
  • May exist as a custom object (Z*/Y*) in this system that can be reused
  • Needs to be built from scratch
• Sketch the data flow: where data comes from, how it's transformed, where it goes
• Identify integration points: other systems, APIs, IDocs
• Consider error handling strategy: how errors are surfaced to the user
• Consider authorization and performance needs (expected data volumes)

Present this as a capability breakdown — not specific object names yet. Those come after research.

Example:

Capabilities needed:

1. Read sales order data from SAP tables
2. Validate order data against business rules
3. Calculate pricing (may reuse existing pricing FM/class?)
4. Send confirmation email to customer
5. Update custom status table
6. Log all processing steps for audit

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Step 4: Research Existing Objects

For each sub-task identified in Step 3, search the SAP system for reusable objects.

Actions:

• For each capability/sub-task, search for:
  • Custom objects (Z/Y)** that already do this or something similar — these are high-value reuse candidates
  • Standard BAPIs, FMs, classes that cover the functionality
  • Tables and structures you'll need to read from or write to
• For every object you find that looks promising:
  • Read its signature: get exact parameter names, types, and structures
  • Read its code to verify it actually does what you expect
  • Check quality: is it well-written? Does it handle errors properly?
• For tables and structures:
  • Confirm field names and data types
  • Check table keys and indexes

NEVER assume an object exists or guess its parameters. Every object and every parameter must be verified against the live system.

Run searches in parallel when possible — search for multiple sub-tasks simultaneously.

Report findings to the user: "For email sending, I found ZCL_EMAIL_HELPER=>SEND which takes X, Y, Z. For pricing, there's no existing custom object but standard FM PRICING_GET_CONDITIONS exists."

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Step 5: Detailed Code-Level Plan

Now — using research results from Step 4 — define the concrete architecture and detailed design.

Actions:

• Decide what objects to create:
  • Which classes, interfaces, exception classes, reports, FMs, tables, CDS views?
  • Name them following Clean ABAP naming rules (load the clean-abap skill if not already loaded): descriptive names, snake_case, no Hungarian notation, nouns for classes, verbs for methods
  • Define each object's responsibility
• For each class/FM:
  • Define methods and their exact signatures (importing, exporting, returning, raising)
  • Specify which reusable objects (found in Step 4) are called, with which parameters
  • Define the data flow through each method
  • Define error handling: which exceptions are raised/caught at each level
• Map out the complete execution flow:
  • Entry point → validation → processing → output
  • What happens on success vs failure at each step
• Include specifics:
  • SELECT statements with exact field and table names (verified in Step 4)
  • BAPI/FM calls with exact parameter mappings
  • ALV field catalog or CDS annotations
  • Authorization checks with exact auth objects

Share this detailed plan with the user for confirmation before writing code.

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Step 6: Write the Code

Only NOW do you write code.

Rules:

• Follow Clean ABAP rules (if the clean-abap skill is available, load and use it)
• Use modern ABAP syntax appropriate for the system version identified in Step 2
• Every object/parameter reference in your code must have been verified in Step 4
• Implement proper error handling as designed in Step 5
• Add meaningful ABAP Doc for public APIs
• Keep methods small and focused

If you discover during coding that you need an object you haven't researched, STOP and go back to Step 4 for that object before continuing.

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Key Principles

• Questions > Assumptions: Ask the user rather than guess. One question now saves an hour of rework.
• Standard > Custom: Always check if SAP provides something before building custom.
• Verify > Trust: Never trust your training data for object names or parameters. Always verify against the live system.
• Plan > Code: More time planning = less time debugging. The plan IS the deliverable — code is just the implementation.
• Incremental confirmation: Get user buy-in at Steps 1, 3, and 5. Don't surprise them at Step 6.