Look for deeply nested custom workflows, unclear ownership of old approval logic, undocumented integrations, and repeated efforts to mimic legacy behaviour exactly in the target platform. Those are strong signals that the programme is re-platforming complexity rather than simplifying it.
What signs show the migration is preserving legacy complexity instead of reducing it?
The clearest warning sign is when the target SAP IDM environment starts looking like a 1:1 copy of the old one. Deeply nested custom workflows, duplicated approval paths, and exception handling that exists only to preserve old behaviour usually mean the programme is lifting technical debt forward rather than retiring it.
Another sign is that nobody can explain why a rule, integration, or role exists without referring back to the legacy system. If the migration team depends on tribal knowledge to justify design choices, the new platform is inheriting undocumented business logic instead of becoming easier to operate.
A third indicator is that every change request seems to require special handling because the target state was designed around exceptions rather than standard patterns. That typically shows up as fragile workflow branching, local overrides, and repeated rework whenever downstream systems or owners disagree with the old model.
Which operational patterns usually reveal excess technical debt early?
Look for migration work that is dominated by reconciliation rather than simplification. If teams spend most of their time matching legacy approval chains, preserving one-off interface behaviours, or keeping obsolete roles alive just so nothing breaks, the project is reproducing historical complexity instead of rationalising it.
Undocumented integrations are especially important. When interfaces are discovered late, reverse engineered from runtime behaviour, or maintained by a single subject-matter expert, the migration is exposed to hidden coupling and brittle dependencies. That is a strong signal that the programme is carrying forward unbounded design assumptions.
Repeated efforts to mimic legacy behaviour exactly are also revealing. In a healthy migration, you expect some behaviour to change because the platform is being modernised. If the design goal becomes “make the new system act identically,” the team is often optimising for continuity at the expense of maintainability, testability, and future change velocity.
How should practitioners separate necessary compatibility from harmful debt?
The useful distinction is whether a legacy behaviour is still a business requirement or merely an artifact of the old system’s design. Some compatibility is justified during cutover, but if the same exception paths remain after go-live without an exit plan, they become permanent debt. A migration should preserve outcomes, not necessarily the exact mechanics that produced them before.
Ownership is a practical test here. If no current owner can defend a rule as still needed, or if ownership sits with a legacy support group that has no authority in the target platform, the design has likely inherited controls and approvals that no longer reflect how the business operates. That creates friction every time the process changes.
Good migrations reduce the number of places where business logic lives. When the same approval logic is duplicated across workflows, scripts, and interface layers, every future adjustment becomes risky. Consolidation, standardisation, and explicit documentation matter more than preserving every historic edge case.
Risk and Threat Considerations
Technical debt in an SAP IDM migration is not just an efficiency issue. Hidden workflow complexity, undocumented dependencies, and inherited approval logic create operational exposure because failures are harder to predict, troubleshoot, and recover from when the target platform must preserve too many legacy exceptions.
Failure mechanism: Legacy rules are copied forward without being revalidated, so the new environment accumulates brittle branching, unclear responsibility, and fragile integrations that only work while the old assumptions remain true.
Impact: The result is slower change delivery, higher defect rates, more difficult access governance, and greater outage or control failure risk when a downstream system, owner, or approval path changes.
Practitioner Guidance
What to verify: Ask whether every non-standard workflow has a named business owner, a documented reason to exist, and a retirement date. If any of those three are missing, treat the item as debt rather than as a requirement.
Common mistake: Treating exact behavioural parity as the definition of success. In practice, parity should be limited to truly mandatory controls or legal/process obligations, not extended to every historic quirk of the old platform.
What good looks like: The target state uses fewer custom branches, fewer hidden dependencies, and a clearer split between standard platform logic and genuinely exceptional business cases. Teams can explain approvals, integrations, and overrides without relying on legacy tribal knowledge.
Practitioner takeaway: If the migration cannot simplify the approval and integration model, it is probably preserving the debt that caused the migration problem in the first place.
Related resources from NHI Mgmt Group
- How do you know whether your identity stack is creating too much technical debt?
- What are the signs that a log pipeline is carrying too much unnecessary data?
- What are the signs that an SAP S/4HANA migration plan is too late or too narrow in scope?
- What are the signs that application teams are still carrying too much responsibility for security and tracing?