System integrations -- strategic phasing or waterfall implementation? [Q&A]

As organizations continue to navigate complex system integrations, one critical decision that arises is whether to embrace strategic phasing or waterfall implementation. The choice of approach can shape the success or failure of projects, particularly when dealing with large-scale ERP consolidations and replacements.

We spoke with Scott Maggiolo, SVP of information technology at Ribbon Communications to understand the pros and cons of each and how the decision is not one-size-fits-all.

BN: What are some of the biggest challenges and complexities you’re seeing in the tech landscape this year?

SM: From evolving compliance demands and AI integration to market saturation and shifting customer expectations, there’s no shortage of challenges for tech teams right now. Internally, many organizations are also grappling with the tall-order task of managing complex large-scale system integrations -- particularly enterprise resource planning (ERP) consolidations and replacements. These projects aim to unify multiple ERP systems into a single source of truth, helping streamline operations and improve decision-making across the business.

As companies take on these major initiatives, a critical decision that can make or break the success of the effort is the implementation approach: strategic phasing or a traditional waterfall model? Each has its benefits and tradeoffs, and choosing the right path can significantly impact risk, cost, and long-term outcomes.

BN: Can you break down the difference between a strategic phasing approach and a waterfall implementation?

SM: Both options are effective for rolling out large IT projects. Strategic phasing allows you to break down a big project into smaller pieces, roll out each part individually, and build on the success of each phase. With recovery time after each leg of heavy lifting, companies will be well positioned to take on the next phase, but it’s not a perfect science. When working bit by bit in a large-scale integration, it’s common to have some ‘throw away work,’ because you’re operating in a trial by error format. You may also be working with two different systems, making it difficult to consolidate data.

In contrast, waterfall implementation is a more traditional 'big bang' approach: everything is planned upfront in sequential phases and launched all at once. Think of waterfall implementation as the long, linear road. This management methodology has great outcomes for streamlining processes at lower costs but carries more risk -- a single failure during cutover impacts the entire process.

BN: What are the main pros and cons of each approach when it comes to big projects like an ERP replacement?

SM: Strategic phasing offers more flexibility. You can adjust as you go, reduce risk, and get ROI from each phase. But it may involve working within two systems simultaneously or redoing work later.

Waterfall is faster in execution once planned and avoids temporary duplication. However, the planning process is much lengthier and the risk at go-live is higher as it impacts many functions at the same time. This means that there’s a higher likelihood of catastrophic failure that could cause a domino effect, forcing the project to roll back. If something fails, it affects the entire business and is harder to recover from.

BN: How do you decide which approach is the better fit for your organization and the type of project you’re working on?

SM: No two integrations are alike -- each project comes with its own set of challenges, timelines, and stakeholder expectations. Understanding the complexity of the project, the tolerance for risk, specific timeline, and internal capacity can help guide this decision.

If you're replacing a business-critical system like ERP and can’t afford disruption, phasing is probably the safer option. It also lets teams adapt gradually. But, if your organization is prepared for a major cutover, with strong testing, clear workflows, and unified leadership, waterfall can offer a faster timeline. It also depends on how many systems are involved and how interdependent they are.

A strategic phasing approach can be a manageable path forward for a company navigating budget constraints, organizational complexity or limited business engagement. This method is particularly useful when leadership seeks operational efficiencies without the budget to support a full-scale rollout. Phasing can reduce risk and maintain project credibility in complex operational environments with zero tolerance for disruptions like rollbacks, outages or delays. This approach is also appropriate in situations where IT is staffing the project in addition to its other duties. It is less all-consuming for the IT team, and other departments, which may have little availability or appetite for deep business transformation, have the opportunity to adopt and manage change incrementally.

A successful waterfall implementation requires a different set of circumstances. The organization must be fully committed to transformative change from the top down and have the leadership and resources to support it. This model works best when internal business process leaders are empowered to redesign workflows instead of replicating legacy systems and requires a sufficient budget to enable engagement with a trusted and effective change management partner. This approach also requires clear business process ownership, strong internal leadership, and sufficient staffing to support the project from start to finish. This kind of structured, end-to-end transformation is most effective in stable environments where requirements are well understood and unlikely to change, enabling appropriate focus and uptake.

BN: What challenges should teams expect if they go with a phased approach, like working across two systems or redoing some work later?

SM: With a phased approach, there’s often a period where you’re running parallel systems, which can increase complexity and require extra support. You might also need to invest in temporary solutions that are later retired, which can feel inefficient.

But the tradeoff is lower risk and more learning as you go. It also allows your team to build confidence and fine-tune processes between each phase. Good planning and communication are key to making this approach work smoothly.

BN: If a team decides to go with a waterfall approach, how can we best prepare for the risks that come with doing everything at once?

SM: Start with detailed planning and stress testing. Build contingency plans for the cutover and have rollback options ready. Make sure everyone, from IT to business stakeholders, is aligned and prepared.

Training is crucial, too, for ensuring smooth adoption and maximizing ROI. When you flip the switch, users need to be able to hit the ground running. Waterfall can work very well, but it’s not forgiving. Investing in preparation and having an experienced project leadership team is key to avoiding costly surprises. For the tech component, training must be hands-on, especially when implementing a new ERP system. This is especially critical when merging legacy tools with more evolving technology -- everyone must be on the same page to ensure success. Change management is also a key factor. New integrations ultimately mean a change in operations, whether it brings more cross-collaboration or just a shift in the way teams work.

For both approaches, total alignment is the bottom line to a successful integration, no matter how complex.

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