Blending Waterfall and Agile (Hybrid Delivery): A Practical How-To Guide
Hybrid project delivery is an approach that combines elements of traditional plan-driven (waterfall) project management with agile delivery practices. Hybrid approaches are common in environments where some aspects of the project are well-understood and benefit from detailed upfront planning, while other aspects are less certain and benefit from iterative delivery and frequent feedback. They are also common in organisations that have made significant investments in waterfall governance structures (stage gates, earned value management, change control boards) and want to introduce agile practices without abandoning their existing governance.
In 2022, hybrid delivery is the practical reality for many public-sector and capital-project organisations. Pure waterfall is too rigid for many complex projects; pure agile is difficult to reconcile with the fixed-scope, fixed-price contracts and governance requirements of public sector capital delivery. Here is a practical guide to making hybrid delivery work.
Step 1: Separate What You Know from What You Need to Learn
The starting point for hybrid delivery design is distinguishing between the parts of the project that are well-understood (where traditional planning is appropriate) and the parts that are uncertain (where iterative delivery is appropriate). A capital infrastructure project might have well-understood regulatory requirements and a fixed physical design standard -- these elements can be planned conventionally. But the technology integration or the stakeholder engagement approach might require iterative development and frequent course corrections -- these elements benefit from agile practices.
Step 2: Design the Governance Bridge
The most common failure point in hybrid delivery is the governance bridge -- the point where agile team outputs must be integrated into waterfall governance structures. A Scrum team that delivers a working increment every two weeks produces deliverables that do not map neatly onto a waterfall project schedule or a monthly earned value report. Designing the bridge means deciding: how do Sprint outputs get reported in waterfall governance terms? How does the change control board handle backlog changes? What does a gate review look like for an agile component of a hybrid project?
Step 3: Manage the Interface Between Workstreams
Define the integration points between agile and waterfall workstreams explicitly. An agile technology workstream and a waterfall infrastructure workstream that must deliver simultaneously need explicit integration milestones -- points at which the agile team's current state must be compatible with what the infrastructure workstream expects.
Use a programme-level plan to coordinate waterfall and agile workstreams. The programme plan shows the major milestones and dependencies between workstreams. Within each agile workstream, the Sprint backlog drives daily work. But the Sprint must be planned with awareness of the integration milestones in the programme plan.
Avoid letting the waterfall workstream set the pace for agile workstreams. In a hybrid project, there is often pressure to synchronise agile workstreams to the waterfall schedule -- to make the agile team's output cadence match the waterfall reporting periods. Resist this: the agile workstream should maintain its own cadence, and the waterfall governance should be adapted to accommodate it.
XNM provides project management advisory services to public-sector and capital-project clients, including hybrid delivery design and governance. Reach out to XNM's program & project delivery advisory team to discuss hybrid delivery design for your project.