System integrators built the integration ecosystem for most enterprise businesses.

Capgemini, Deloitte, IBM, Accenture, Infosys, HCL, TCS, and the rest of the named global SIs continue to deliver excellent transformation work. We have an existing breakdown of the top global system integrator companies that covers the category in detail.

This article asks a different question. Not which SI is best for your transformation programme. The question is: when integration work is part of your day-to-day operations rather than a one-time project, is the SI model the right shape for it?

Why you should consider an alternative to SIs

The biggest challenge to SIs is not competence and ability to deliver results. It’s that most system integrators are built as project-shaped suppliers. They are excellent at one-time transformations and structurally mismatched to ongoing integration work.

The mismatch shows up as the maintenance backlog. SI engagements end at handover. Each subsequent change becomes a new project, scoped and quoted at day rates. The cost of running the integration through the SI typically runs three to four times the cost of building it, over a three-year horizon.

Managed integration services like ONEiO deliver the outcomes you would hire an SI for, through a continuous service model rather than a project engagement. Same outcome. Different operating model. Different economics.

This is not an argument that SIs are wrong. They remain the right partner for transformation programmes, ERP rollouts, and complex one-time builds. The mismatch is specifically with continuous integration work.

Decide by work shape. Project work goes to an SI. Operational integration work goes to a managed service. Most companies need both?

For most companies, the honest answer is no. This is the case for routing your integration work to a different operating model, while keeping your SI relationship for the work it is genuinely best at. Here is where you’re likely to choose an integration service over a project-based SI.

What system integrators are excellent at

System integrators are consultancies organised around delivering complex, multi-system engagements as projects. ERP rollouts. Cloud migrations. Industry-specific platform implementations. Post-merger systems consolidation. The work that needs a hundred specialists for nine months and then does not need them anymore.

The model is bench-based talent, project methodology, statement-of-work contracting. SIs are excellent at this. The category exists because no other delivery shape works as well for one-time transformation. For transformation work, SIs are rarely the wrong call. Most large enterprises will keep working with them indefinitely.

We wrote a whole book on why the SI model breaks for integration work

Most enterprise integrations do not end. They evolve. Over the past two decades we’ve seen this trend so often we wrote a whole book to explain the consequences to IT service leaders.

The Integration Ops book opens with the diagnosis. Chapter 1 names the pattern: integrations are treated as one-off deliveries, items on a to-do list. Once marked done, the integration recedes into the background. Months later, when it fails, the people who built it may already have moved on. Documentation is thin. Monitoring is thin. Teams scramble to diagnose issues under pressure, often learning about the integration’s design and dependencies for the first time while it is already on fire.

The book calls project-based delivery a trap disguised as a process. The logic seems sound. Define the need, plan the work, build the connection, test it, deploy, close the project. On paper, neat and reassuring. In practice, integrations rarely behave like isolated pieces of work. They live in the spaces between systems, teams, and sometimes entire companies. They carry responsibilities that outlast any single project. Once you treat them as temporary efforts, you almost guarantee long-term fragility.

A quick integration to connect two ticketing systems slowly becomes a recurring bottleneck during every system change. A flow that was never fully documented turns into a black box nobody wants to touch. An interface originally built for one customer becomes quietly reused for others without expanding its support, creating unknown dependencies and invisible risks. Over time, every project leaves behind a small pile of complexity.

Often the customer and service delivery perspective are different. The SI completed the project. The SI is not structured to live with the project for the next ten years. That is the gap, and it does not close by hiring a different SI. It starts with treating integrations differently.

The arithmetic of project-shaped supply

Each integration change is too small to be a real project. But it is exactly the size that fits an SI’s contracting model. So the SI quotes each one, runs it as a small engagement, and hands it back. The customer pays for project structure on what is really continuous operations work.

The build cost is the headline number. It gets approved at procurement. It ends up in the case study. The maintenance cost over the next three years usually runs three to four times the build cost.

This is not visible at procurement time. It only becomes visible after year two, when finance asks why the integration line item is bigger than the build budget was. The SI did not overcharge. The customer did not underplan. The model itself produces this outcome whenever you use a project-shaped supplier for operational-shaped work.

The same point applies more broadly to integration economics. We cover the underlying decision in detail in our build versus buy guide for integrations, and our breakdown of integration service providers compared covers how SIs, iPaaS consultants, and managed integration services line up against each other on delivery model.

What changes when integration work moves to a service model

The Integration Ops book frames the alternative as four mindset shifts. From project to product. From one-off efforts to repeatable patterns. From manual fixes to proactive automation. From tribal knowledge to structured ownership.

For service providers, the implications are significant. With an Integration Ops operating model, providers can productize integrations as part of their offerings. Instead of treating integration as a negotiation point in each contract, with uncertain scope and risk, they can present clear integration options with defined behaviours and SLAs. Customer and partner onboarding becomes faster and more predictable. Integrations can be delivered as part of standard service packages, reducing time-to-value and lowering friction in sales and delivery.

Operationally, this model supports higher SLAs across systems and organisations because the integration layer is engineered as a reliable service in its own right. Providers can scale their operations without linear increases in headcount because the platform absorbs much of the complexity.

For enterprise IT teams, the same operating-model shift removes the bottleneck of waiting for an SI to scope and deliver every change. The integration capability becomes something the team consumes, not something the team has to keep contracting for.

How to choose between an SI and a managed integration service

Three questions before signing the next SOW with a system integrator:

1. Is this a project or an operation? If the work has a defined start, a defined end, and a clean handover at the boundary, it is a project. SIs are organised for this. If the work needs to keep working through change for the foreseeable future, it is an operation. SIs are not organised for this.‍
2. How much of last year’s SI spend was project work and how much was operational work being billed at project rates? Many CIOs have not done this exercise. Take last year’s spend with the SI. Mark each line item project or operational. Sum the operational column. That number is what is currently being paid at the wrong economic shape. It usually surprises the people who do the exercise.‍
3. What does “who fixes this when it breaks” look like in two years? Under an SI engagement, the answer is a new SOW, scoped and delivered at day rates. Under a managed integration service, the answer is the service team, included in the subscription. The difference compounds with every change.

The five strongest alternatives to SIs for integration work

1. Managed integrations (ONEiO)

Managed integrations operate the integrations on the customer’s behalf. Continuously. ONEiO is the leading example.

The engagement model is service ownership rather than project delivery. Implementation, monitoring, maintenance, resolution. All included. The integration is built once and operated forever, by the same team, under one predictable subscription. You are not subscribing to a tool. You are subscribing to an outcome. One predictable cost that covers everything. No consultant day rates. No surprise invoices. No mystery.

For data residency and compliance, a managed service gives you full control over where your data is processed and stored. Visible, auditable, and answerable to whoever is asking.

Best for: enterprise IT teams and service providers running integrations the business depends on, particularly where the integration count is growing or the change cadence on either side is accelerating. The pattern is well established with our customers. Our managed integrations approach for MSPs explains how scaling customer integrations as a service replaces the per-customer engineering burden that catches most service providers as they grow.

2. iPaaS plus internal team

An iPaaS platform (Boomi, MuleSoft, Workato, others) gives you the infrastructure to build and run integrations. Your internal team operates them. This is a halfway model. The platform vendor owns the platform layer. Your team owns the configuration, the operations, and the outcomes.

This works when you have continuous internal capacity to operate the platform. It is the same operating-model question that catches teams using sync tools. The platform is available. The outcomes are your responsibility.

We cover the iPaaS choice in detail in our 10 best iPaaS solutions guide.

Best for: enterprises with broad iPaaS needs across data, applications, APIs, and AI agents, and the engineering capacity to own the platform.

3. iPaaS plus consultant retainer

The iPaaS platform plus an SI or specialist consultancy on retainer to operate it. This is the de facto model in many enterprises that adopted iPaaS without changing their delivery shape.

It combines the platform cost with the SI day-rate cost. It does not solve the structural mismatch between project-shaped supply and operational work. It softens it by making the consultancy’s involvement continuous rather than project-by-project, but the economics still favour the consultancy and the accountability still sits with the customer.

Best for: enterprises that have already invested in iPaaS and need a transition path before considering a fuller managed-service model.

4. Build it yourself

For some teams, the answer is genuinely to build and operate integrations in-house, with internal engineers and platform teams. This works when the integration is a strategic differentiator, when the team has the capacity and skills, and when the rate of change is manageable.

It does not work when integration is a means to an end rather than a core competency, when the team is already overloaded, or when the change rate exceeds the team’s bandwidth to respond.

Best for: organisations where integration is a strategic differentiator and the team has the capacity to operate it.

We cover the underlying decision in detail in our build versus buy guide.

5. Specialist boutique integrator

Smaller, specialist integration consultancies (regional or vertical-focused) sit between the global SIs and managed integration services. They tend to deliver projects with closer attention to specific platforms or industries, often at lower day rates than the global SIs.

The operating model is still project-shaped. The advantage over a global SI is depth of platform-specific expertise and a closer working relationship. The disadvantage is the same as any project-shaped supplier: each change is a new engagement.

Best for: enterprises with specific platform needs (e.g. a deep ServiceNow or Salesforce focus) where boutique expertise outweighs the operating-model question.

What changes when integration becomes a service

The difference between an SI engagement and a managed integration service is what you are buying. With an SI, you are buying a project. With a managed service, you are buying an outcome. Three things change at the same time.

Get predictability. One predictable cost that covers everything: implementation, maintenance, monitoring, resolution. No SI day rates. No surprise SOWs. No mystery. The integration cost stops moving from quarter to quarter, because the model has stopped relying on incidents to generate revenue for somebody else.

Get transparency. ONEiO runs on transparent integration technology. No black-box logic. No code only a specialist can read. It works with your entire environment, whatever tools your team runs, whatever platforms your partners use. Cleaner integrations, full visibility, and a foundation that grows with your business. For data residency, you get full control over where your data is processed and stored. Visible, auditable, and answerable to whoever is asking.

Get outcomes. The integration is ours to run, and ours to be accountable for. Your technical team stops fielding integration problems. Your business team starts seeing the outcomes they were promised. Nothing breaks. That is the guarantee. One customer recently expressed this well: “For the first time, I can actually see what my integrations are doing. No guesswork. No waiting for something to break before I find out.” IT leader, global managed services provider

Time to change?

SIs built the integration ecosystem. They are not going anywhere. The categories of work where they win, transformation, complex one-time delivery, are not shrinking.

What is changing is the recognition that integration as ongoing work does not fit their delivery shape. It never did. It just took two decades and a handful of new operating models for the alternative to exist at all.

The teams figuring this out are not replacing their SI. They are routing the right work to the right shape of supplier. Project work to the SI. Operational integration work to a managed integration service. The maintenance backlog stops growing. The three-times-cost arithmetic flips back. The SI relationship gets stronger because it is used for what it is good at.

Time to change? Schedule a meeting below and talk to us about what a managed integration looks like for your environment.