The two most common strategies for software deployment are the ‘Phased Approach’ and the ‘Big Bang Approach’. Of these two, one carries much more risk – and potential benefits – than the other: the ‘Big Bang’. In fact, I think it would be fair to say that often the biggest bang the ‘Big Bang’ creates is the sound of your project exploding! So, if you decide to go in this direction, you must use an abundance of caution and you should take the time to ensure that this methodology is right for your project. This article will help you decide exactly that.
With that said, let’s start our analysis by defining ‘Big Bang’ versus ‘Phased’.
THE PHASED APPROACH
As you might expect, in the Phased Approach the project is delivered in ‘chunks’. The functionality that is to be included in each phase is determined well before the the development work begins, with the early phases usually focusing on ‘quick wins’ or providing the modules that will be most impactful to the organization.
THE BIG BANG APPROACH
Simply put, the Big Bang strategy involves all modules of your software going live at the same time. In an extreme example, not only would all the modules go live at the same time, but they would go live in all the company’s locations at the same time (although this strategy is used very rarely). However, even if you only go-live with all the modules in one or two locations, this approach is not for the faint of heart!
We will see why in the next sections of the article, where we list the pros and cons of each strategy
PROS OF THE PHASED APPROACH
- Easier to Contain: Because you are only going live with limited functionality in each phase of this approach, if things go wrong, it is much easier to contain the impacts and damage to the organization as a whole.
- Experience Gained: As each phase is deployed, the deployment team gains valuable experience.
This should lead to each successive roll-out incurring fewer-and-fewer issues. - Change Management Requirements Minimized: Because each phase typically affects only a portion of the organization, the demands on the Change Management team are minimized. This increases the chances of a successful deployment, as the solution has to be adopted/utilized by a smaller user community.
- Fewer Issues at Go-Live: Because, again, the scope of each phase is somewhat limited, the number of issues experienced at go-live is much less than with a Big-Bang project. This minimizes the demands on the project team, and allows issues to be resolved more quickly.
- Early Delivery of Benefits: If the team has done a good job of scoping the deliverables in each phase, the business should realize benefits early in the project. This is not only helpful to the organization, but is also good for project morale.
- Cost Savings: As the internal project team gains experience moving from one phase to another, there is every possibility that the increased competence of that team will allow some external consultants to be released. This can result in significant cost savings.
CONS OF THE PHASED APPROACH
- Longer Project Timeline: Because you are delivering the project in smaller pieces, it will take longer for the project team to cover the entire project scope. This could be a significant consideration for the organization if they are under time-pressure to see project benefits.
- Increased Cost: If – as stated above – the Phased Approach takes longer to deliver, it stands to reason that this will also result in increased project cost when compared to the Big Bang.
- Environmental Complexity: If you are delivering only pieces of the system at any one time, for a while (and perhaps for quite a while) your organization will be conducting it’s business using multiple systems. Not only does this make for a more complex business environment, but the fact that interfaces will have to be created to allow the new system to ‘talk’ to the old system will result in a more complex technical environment.
- Organizational Burn-Out: If your Phased Project is delivered over years, you run the risk of encountering ‘organizational burn-out’. The team, and the organization generally, may get tired of being in a constant state of change, and this can result in slower delivery times and a poorer solution adoption by the user base.
PROS OF THE BIG BANG APPROACH
- Less Complex Technical Environment: Because the Big Bang approach delivers the entire solution at one time, you do not have to dealing with a multi-system environment. This translates to a less complex (and
potentially less troublesome) technical environment, as there will be no temporary interfaces connecting the old and new systems - Integrated Business Processes: One of the great benefits of deploying the entire system at once is that – because all business processes are executed in one homogenous system – there is a high-degree of integration among the various business process elements (and departments) within the organization.
- Cost Savings: Generally-speaking, delivering the entire project scope at once is less expensive than delivering it in smaller pieces over a longer period of time.
- Time Savings: As above, a Big Bang approach delivers the entire project in a more timely fashion than a phased approach does. This allows the company to start it’s ‘ROI clock’ ticking sooner.
- Organizational Focus: Because the entire company is typically involved in a Big Bang project, there is a sense that “we’re all in this together”, and the project is highly visible on everyone’s radar. This helps avoid problems with conflicting project and organizational priorities.
CONS OF THE BIG BANG APPROACH
- A ‘Perfect Storm’ of Changes: It is an article of faith in software deployment that business process change (to one degree or another) always accompanies technical change. This could be by design, or simply because the new software does not support the old business process. Regardless of the reason, having business process change and technical change occurring across the organization at the same time makes for a very stressful environment.
- Difficulty in Containing Issues: Because the Big Bang delivers an entirely new system, it is extremely likely that a significant problem with one of the system modules will have a ripple effect on one or more of the other system modules. (This is the ‘down-side’ of having an integrated system.) And if multiple modules are affected by an issue (or issues), the impact on the organization could be dramatic…and recovery will typically not happen overnight.
- Magnified Number of Go-Live Issues: Delivering all modules at the same time means that there will be many, many potential sources of issues at go-live. In fact, in my experience it is not unusual to see Issue Lists containing hundreds of items. And obviously resolving all these issues can take significant time. Will your organization (both IT and the business) be able to cope with this situation?
- Complex Testing Phase: Because of the integrated nature of the solution delivered by a Big Bang approach, you will need to develop a large number of fairly complex test scenarios in in order to test thoroughly (which is essential). This will mean an extended period of time in the test phase, and tracing the root cause of any issues found in such complicated scenarios can take a significant period of time.
- Impact of Issues on User Acceptance: If your Big Bang go-live does not go particularly well (and they are NEVER painless) there is a risk that your user community will get tired of dealing with one issue after another. This could result in poor rates of user adoption, as they find it is easier to do things ‘off-line’ (i.e. in Excel!). This will certainly impact the project’s ROI.
DETERMINING THE RIGHT APPROACH
As I was conducting my research for this post, I came across an article by John Donagher of Lumenia Consulting which contained several questions which can help inform your decision around whether to use a Big Bang or a Phased Approach. These questions are listed below:
- Does the implementation cover a single site or multiple sites? A big bang implementation on a single site is considerably easier to manage than a simultaneous big bang across multiple sites. However interdependencies between sites could dictate that a phased approach isn’t viable.
- Does the implementation cover a single business or multiple businesses? If multiple business units are involved then it might make sense to phase the implementation by trading company or business unit.
- Are there any other competing business activities that need to be taken into account? Factors such as regulatory compliance, acquisitions, new product introductions and other capital expenditure programs can influence the required timescale for an ERP implementation.
- What level of risk is acceptable? The generally held view is that big bang implementations have an inherently higher level of risk. This is because the integrated nature of ERP systems means that a failure in one part of the system can have knock-on effects elsewhere. The scope of a big bang implementation can also mean that full end-to-end system testing is difficult to achieve, and it’s only when the system goes live that all of the interdependencies are fully tested.
SUMMARY
I have often published blogs which discuss the pros and cons or one project management option versus another. And I generally don’t take a position as to which choice is better. I just present information concerning all options and leave it to the reader to decide. However, in this case, I feel compelled to deviate from that approach and say that – unless there is a REALLY compelling case for doing so – do not use the Big Bang approach! In my opinion, the risks simply do not outweigh the benefits.
Certainly, delivering a project at a lower cost over a shorter time-frame has appeal. However, too often I have seen projects fail to realize these benefits because the go-live date is repeatedly pushed out or the warranty period lasts for months and months. At standard consulting rates, it does not take long for the expected cost and time benefits to completely disappear when this happens.
Also, when go-live dates are pushed out, you should keep in mind that this not only increases cost, but it also means that the business is delayed in seeing any benefits from it’s investment. The Phased Approach my take longer overall, but perhaps it’s greatest advantage over Big Bang is that it has a much higher likelihood of delivering real business benefits in the short term.
So, unless your software deployment project is relatively small, focused and deploying to only a few business units, run far and run fast from Big Bang…or you may get swept up in the mushroom cloud!
