During the planning phase of a UKG implementation, one of the earliest and most important decisions is how to structure your go-live rollout strategy. Organizations typically choose between two contrasting methodologies, Big Bang or Phased. Both can lead to successful outcomes, but the journey and plan to get there look very different. Understanding these differences can help customers and consultants align expectations, mitigate risks, and design a rollout that supports long-term adoption.
The Big Bang Approach
A Big Bang HCM implementation means launching all selected UKG modules at the same time, including:
- Timekeeping,
- Scheduling,
- HR,
- Payroll.
This method leads to a “single moment of change” for the entire organization. One implementation go-live date, and therefore, all HCM processes are moving towards this change simultaneously.
Benefits of the Big Bang Approach
A Unified transition
- Users experience a single major shift rather than multiple smaller ones, which can simplify change management, communication plans and training timelines.
Clean data cutover
- Since all modules go-live simultaneously, integrations and downstream processes are aligned from day one.
Quicker time to value
- Organizations looking for rapid modernization or facing regulatory deadlines may prefer this accelerated approach to meet their organizational goals.
No Dual Maintenance Period with simultaneous systems
- Since the goal is a clean cutover from your legacy HCM system to the new UKG system, there is less stress on the organization’s internal teams and systems. They will not need to provide support for both the old and new systems simultaneously.
Challenges with the Big Bang Approach
Higher risk profile
- Because everything goes live at once, defects or gaps can have broader operational impacts. Risk management is critical to mitigate this challenge.
Intensive preparation
- Testing cycles, data validation, and training must be exhaustive. The project team must thoroughly test all processes affected by the new HCM system. They should develop comprehensive test plans early in the project.
Heavy change management load
- Employees must absorb many new processes simultaneously, which can strain adoption during an already stressful deployment of a new system. Ensure your change management plans are in place to mitigate this risk.
The Phased Approach
A phased implementation breaks the project into multiple go-lives, often starting with foundational modules (such as Timekeeping) before adding others (such as Advanced Scheduling or HR/Payroll) later.
Benefits of a Phased Approach
Lower operational risk
- Issues are confined to a smaller functional area, simplifying troubleshooting. The overall phase is smaller in scope and complexity.
Learning curve is not as steep
- End-users adapt to new processes incrementally, improving comfort and adoption. Training is easier to reinforce, module by module.
Flexible refinement
- Early project phases provide organizational insights that can shape configuration decisions in later phases. Using this approach helps improve future rollouts by enabling both the project team and the wider user community to learn from earlier go-lives.
Challenges of the Phased Approach
Longer overall timeline
- Multiple phases require extended project oversight and involvement from both consulting teams and internal project teams.
Temporary complexity
- A phased approach to your HCM implementation creates a hybrid state for a period of time. This hybrid means that some processes live in your new UKG system, and others remain in legacy systems, which can introduce short-term operational overhead and increased load/demand on internal staff.
Repeated change cycles
- Each phase requires its own communication, testing, and training plans. The development of multiple plans is a significant consideration for the change management and training strategy. When rolling out initiatives across different groups, these plans can be adapted to fit the unique needs and characteristics of each employee population.
Choosing What’s Right for Your Organization
The decision ultimately hinges on organizational readiness, resource availability, and organizational appetite for change. High-maturity teams with strong testing capabilities may thrive with a Big Bang approach. Organizations needing stability during transformation—or those implementing UKG across large, diverse populations—often benefit from a phased rollout.
Both paths can succeed. The key is making an intentional decision based on planning, realistic timelines, and a clear vision of how your new UKG HCM system will support your long-term HCM strategy. Ready to align your HCM vision with the right UKG implementation strategy? Contact HRchitect and let’s get started.
About the Author
Daniel Sizelove is the Director of UKG Pro Workforce Management Services. Since joining HRchitect in 2022, he has led a team widely recognized for delivering high-quality consulting services to clients worldwide. Dan’s team’s expertise with UKG WFM products, including numerous migrations from Legacy systems such as Workforce Central, UTA, and UTM to UKG Pro WFM, means they have seen it all and will be ready to help you make this critical move with ease.
When Dan isn’t working, he enjoys spending time with his family and playing the occasional round of golf.
Find out more about Dan’s experience on LinkedIn.
