System Integration From Your Business Unit's Perspective

TL;DR

Integration with mature, well-documented platforms is largely a matter of following the playbook the vendor gives you. Integration with less-defined or unsupported systems is far more nuanced — especially for organizations that don’t yet have deep in-house technical maturity. Six practices make the difference: documenting every process up front, involving every affected department, preparing UAT early, monitoring testing continuously, maintaining a tight governance cadence, and planning training and stabilization before go-live, not after.

Two very different kinds of integration

Integrating with well-known platforms that have mature APIs is usually straightforward — you get what the platform gives you, and the use cases are largely defined by the platform itself. Integrating with systems that are less well-defined or less well-supported is a different challenge entirely, and it requires far more discipline, particularly for organizations that don’t yet have strong in-house technical maturity. The following six practices are the ones that have consistently made the difference on the integrations I’ve delivered.

1. Write everything down

Document every process each system needs to manage before any development starts. That list of processes becomes the backbone of test design — the use cases that everything else is built around.

For each process, capture both the inputs (the requirements) and the outputs (the results) for every system involved. That mapping shows exactly where information needs to flow between systems. Combine the process maps with the data requirements to create a detailed scope of work for the developer or vendor. The developer or vendor should, in turn, document their own logic and workflows clearly enough that a new technical user could pick up the integration and understand it quickly.

2. Collaborate to ensure success

No single person will know enough about both systems to be the expert on each side of the integration. If the integration spans more than one department, bring those departments in as stakeholders from the start, not as reviewers at the end.

Integration use cases tend to follow a skewed distribution: roughly 80% are high-frequency, mainstream cases, and the remaining 20% are edge cases that require special logic or manual intervention. Subject matter experts need to identify those edge cases early — ideally with supporting metrics — so the integration is designed around them rather than discovering them during testing. A missed edge case at this stage becomes a missed requirement during development, and a failed test during UAT. The output of this collaboration becomes the developer’s build checklist.

3. Prepare for User Acceptance Testing early

Start preparing for UAT well before it’s actually scheduled. Three things need to be in place: detailed, step-by-step test scripts; a test environment with sample data, built once the scripts are finalized and coordinated with the technical team; and testers who are available and briefed to execute the tests.

4. Monitor testing at every stage

Developers typically build an integration in discrete units, each tested in isolation — for example, confirming that if action A occurs in the lead system, action B occurs as expected downstream. Solid unit testing, paired with periodic QA spot checks, is what keeps the number of bugs surfacing during UAT manageable.

Ask the developer for regular status reports showing the trend of successful tests against the agreed use cases and scripts. That trend is one of the clearest signals of whether the integration is on track. Without it, you won’t know whether the build is suitable for production until you test it yourself — by which point a schedule slip of several weeks is a real risk. Once code moves into user testing, stay closely coordinated with the developer so that bugs found during UAT get fixed quickly.

5. Maintain a governance cadence

Set up governance to manage the day-to-day challenges that come up during delivery, and give the team a clear forum for raising risks and concerns about development progress or vendor performance. Document the decisions made in that forum. Keep participation limited to the people who actually have the knowledge and authority to make tactical calls, and share outcomes with the wider senior stakeholder group separately.

The developer or vendor should give regular updates on development progress, unit testing results, and deployment readiness. On one integration I delivered, even with daily standups in place, we did not always have the right people in the room — which led to rework and missed use cases once the code reached testing. Better stakeholder awareness earlier in the process would have shortened the overall timeline. Governance is the glue that holds the whole effort together.

6. Plan training and stabilization before go-live

Once UAT passes and the code moves to production, end users still need training to operate and maintain the system going forward. The stabilization period that follows requires close monitoring — spot-checking outputs and actively managing any manual tasks that remain. Training should include hands-on oversight while business-as-usual activity ramps up, and the developer’s technical documentation should be converted into practical training guides for the team that will own the system day to day.

What this delivers

On one integration built around these six practices, we improved the efficiency of the system and reduced the workload of the affected departments by roughly 50%. None of the six practices are complicated individually. The discipline is in doing all of them, in sequence, before the pressure of a go-live date makes shortcuts tempting.

From the field: I applied this same integration discipline — process documentation, edge-case mapping, and governance cadence — across a digital banking transformation involving 40-plus delivered projects. Read more in Services: PMO & EPMO Setup.