Whether you are implementing your first ERP system or replacing an old one, choosing the right ERP implementation phasing is important to project success. The three main ERP implementation options are Big Bang, Phased, and Parallel.

Your ERP Implementation choices are:

• Big bang - Implementation happens in a single instance. All users move to the new system on a given date.
• Phased rollout - Changeover occurs in phases over an extended period of time. Users move onto new system in a series of steps.
• Parallel adoption - Both the legacy and new ERP system run at the same time. Users learn the new system while working on the old.

Situational Questions

• How resistant to change is the team?
• Are the majority of employees able to learn quickly?
• What level of risk is reasonable?
• What is our time frame?
• Does the budget allow for higher spending on implementation?

Big Bang

The big bang approach refers to when all parts of the new ERP “go live” (are turned on) all at once. This is the fastest approach, because everyone must use the new system once it is live.

Benefit: This approach has the shortest implementation time. Big bang is often the most affordable option because there aren’t two systems running simultaneously.

Limitation: Employees need to pick the system up as quickly as possible. Reduced productivity can occur due to difficulty adjusting to the new system and learning different processes. Any issues that arise will need to be dealt with immediately, which could lead to other problems.

Phased Rollout

This ERP implementation tactic features a predefined set of steps for slowly transitioning from the old to new system. Organizations can release modules in phases, usually taking 2 to 4 weeks between releases.

Benefit: Risk is substantially decreased with a phased rollout ERP implementation. Employees can learn as each new phase is implemented. This option often retains the highest amount of productivity.  Fixes are also easier to make since they are typically limited to one or two modules at a time.

Limitation: The phased rollout implementation requires a connection between old and new systems, which increases costs. Introducing the different phases does draw out the implementation time. This extended period of implementation can cause continuous disruptions over the course of the project. Phased rollout often takes longer than other implementation methods. People may experience implementation fatigue by being in a continuous state of change.

Parallel Adoption

The parallel ERP implementation phasing strategy involves operating the new and old system at the same time. Users typically train on the new system, but work out of the old system until the switch is complete.

Benefit: This is the least risky strategy. People have a lot of time to train on the new system. Those that are resistant to change do well with this method.

Limitation: Parallel adoption is often the most expensive of the ERP implementation phasing strategies. Employees can become frustrated from dual data entry. Errors are made most often in this strategy from forgetting to enter information in both systems.

Hybrid Approach

The hybrid approach combines the above three approaches. You may roll out some Odoo ERP modules quickly using a big bang ERP implementation and then rely on a phased strategy for the remainder of the rollout. A parallel adoption might be added for mission-critical processes that your corporation depends on.

How to Choose the Right Strategy for You

Organizations have different needs, and there’s no one-size fits all approach when it comes to Odoo ERP implementations. Questions you must ask yourself when deciding between these methods include:

1. How large is our Odoo implementation?
2. What is our risk appetite?
3. When can we hope to see a return on investment?
4. What is our budget?

A big bang strategy could also be too risky if you are a large firm that’s trying to implement several ERP modules directly. In distinction, a smaller organization with a healthy risk appetite could discover a big bang approach best.

If you’ve room in your budget for it and you’re okay with a delay before you see a return on your investment, a phased approach could be the best for you.

Making the Decision

After reading the positive and negative points of each method, you should have an idea of what might work. For some companies, there may not be much of a choice because of fixed constraints. It all comes down to your time frame, budget, resources, and comfort with risk.

Leverage Consultant Expertise

History of past success (or failure) is a good indication of what will happen in the future. An ERP consultant will be able to guide you towards the right path. Many seasoned consultants have seen all three ERP implementation phasing methods, providing a comprehensive picture. They will have insight into which option may be best for your situation, employees, and company.

Read on: Implementation Methodology - The ultimate guide to successfully implement and sell Odoo projects.

FAQ: The implementation methodology selection tool