Big Bang vs. Phased Implementation: Pros and Cons

December 1, 2020

Written by Chris Henien


Congratulations, you have decided to implement a new HCM system! One of the most important decisions impacting the project will be whether to use a Big Bang or a Phased approach. Let’s talk about what each of these implementation approaches consists of and the pros and cons of each.


Big Bang Implementation

This method is an all-in-one approach where the goal is to implement every single module that you will be using in your new solution on one go-live date. All employee groups, locations, modules, and integrations are deployed during this one significant project milestone. With this approach, the entire company will begin using the software at once, and all legacy systems will be decommissioned. Because all end-user groups will go live simultaneously, this implementation method will also have the lowest overall cost and shortest timeline. The impact of that is that you will realize your return on investment sooner. However, the big bang approach does increase the inherent risk associated with the project. It can be difficult to complete thorough testing for all groups in the naturally shorter timeline. This may decrease your initial productivity as you work through any issues in your production system. Productivity may also be negatively affected due to the difficulty of training all employee groups before go-live.



Phased Implementation

This implementation method consists of multiple go-lives that could be divided by location, modules, or functionality. This approach will limit the exposure of your new system within your organization and allow/require utilization of legacy systems until all go-lives are complete. This approach provides additional time to fully test the system prior to each go-live to ensure that the new solution meets the business needs. A phased implementation approach also provides extra time to train employees, increasing end-user productivity during the initial use of the system. However, these benefits come at the expense of a longer timeline and increased costs associated with each additional go-live.


So, what’s the best option? This will vary from organization to organization and really comes down to the preference of the business and the stakeholders in the project. It is always best to consider both implementation methods and to determine the pros and cons of each.

HRchitect’s consulting services cover the full lifecycle of HCM systems. Our team of expert consultants work collaboratively to move our clients through each phase of the lifecycle – from creating a strategic roadmap around their HCM technology architecture, through selecting and implementing new systems, to change management and beyond. Contact HRchitect today and let us guide you to make the best decision on your next implementation project.

Chris Henien joined HRchitect in 2016 as a Technical Consultant and has quickly been promoted through the ranks holding positions including Technical Delivery Manager, and his current role, Workforce Management Solutions Delivery Manager for several rapidly expanding consulting practices.