When you’re rolling out a new Warehouse Management System (WMS), phasing your implementation is almost always the safer bet over a Big Bang go-live. In our post, Big Bang or Phased: The WMS Decision That Keeps People Up at Night, we made the case for why phasing manages risk, builds expertise, and lets you adjust before problems replicate across your network. But “phase it” isn’t a strategy on its own. There’s no single right way to do this, and the approach you choose depends on your operation, your risk tolerance, and how your network is structured.
Some approaches consistently work better than others, though. Here’s how to think through the options.
Phasing by Facility (Most Common and Recommended)
If you’re phasing by facility, your first site matters more than any other decision you’ll make in the rollout. It sets the tone for everything that follows.
The site you choose needs to strike a specific balance:
- Representative enough to surface real issues. A small, simple facility won’t teach you what you actually need to know.
- Contained enough to limit risk. Avoid your highest-volume or most complex facility. Something will go wrong, and you need room to recover.
- Staffed with strong operators. This is not the place for a struggling team. You need capable leadership and adaptable staff who can learn quickly and give you meaningful feedback.
The sweet spot is a mid-sized facility that reflects your broader operation without putting the business at risk if things don’t go perfectly.
Phasing by Process
Rolling out receiving first, then put-away, then picking sounds controlled on paper. In practice, warehouse processes are tightly interdependent. Running partial workflows in the WMS while others stay on legacy systems creates workarounds, added complexity, and temporary integrations that exist only to be torn out later. It’s a commonly requested approach, but not one we recommend often. It can work in highly controlled scenarios, but more often than not, it introduces more risk than it removes.
Where it does work well: a new facility. We’ve had clients start with receiving to fill the building, then transition fulfillment in phases by order type or customer. Since there’s no active operation being disrupted, this approach can actually reduce risk and create a more controlled ramp-up.
Phasing by Customer or Business Line
This approach works best when operations are already clearly segmented, with separate inventory, workflows, and order profiles.
It lets you:
- Transition gradually within a single facility
- Use early phases as a training ground
- Reduce operational disruption
This is especially effective in 3PL environments, where customer separation already exists as part of the business model. The same logic applies to business lines: if products, inventory, and order flows are distinct, you can phase by business unit in much the same way.
In practice, this often becomes a hybrid: phasing by business line within a facility, then scaling across distribution centers. As we covered in our Big Bang or Phased post, the goal at every stage is containing risk while building expertise, and this approach does both at once.
When Approaches Combine: A Real-World Example
One of the more ambitious rollouts we’ve supported shows what’s possible when these approaches get combined intelligently. A fitness company needed to deploy across three large distribution centers and more than forty smaller facilities, all within eighteen months.
Major sites went first, one at a time, generating ROI while the team built expertise. Then the smaller sites followed in accelerating waves, culminating in a weekend where a dozen locations went live simultaneously. The timeline looked unattainable at kickoff, but each successive rollout made the next one faster and cleaner. By the end, the team was executing at a pace none of us would have predicted.
That’s the compounding value of phasing. You’re not just managing risk, you’re getting better as you go.
Have questions about which WMS phasing strategy fits your operation? Contact Cornerstone Edge.