According to a survey of merchants conducted by the e-tailing group, most firms decide to re-platform because they outgrow their existing ecommerce platform or the functionality of their current setup is inadequate for their needs. Sounds familiar, right? For some online retailers, what’s also common—not to mention painful—is the disconnect between the business goals that drove the decision to re-platform and the Frankensite that comes out on the other side. And when ambitious merchants piggyback a redesign onto the re-platforming project, the entire process gets complicated fast.

Where do things go wrong? Generally, the process breaks down due to:

• choosing the wrong platform (it doesn’t align well enough with your core business needs, limits future growth, doesn’t integrate well with your current systems, etc.)
• poor planning/management that leads to blown budgets, missed deadlines, runaway lists of features, frequent changes in direction, etc.
• losing focus on the customer’s needs, the reason to undergo this tremendous shift in the first place

Even if you’re one of the few lucky firms that operationally pulls off a re-platform and redesign without too many headaches, there’s one more hurdle to consider: When you make a slew of radical changes to your website all at once, you’re hard-pressed to determine what’s now driving your performance metrics. Did conversion numbers drop off a cliff because the product page is too busy or because the logic driving the product recommendations feature is a little off? Did time on site increase because visitors like the new navigation or because they’re struggling to find what they came for? You’re back to square one on your benchmarks.

A better way to handle the redesign project, whether it’s connected to a re-platform or not, is to commit to incremental changes vetted by A/B testing. By testing different treatments as you evolve your current site to a new design, you can roll out successful treatments while easing existing customers into the new look.

The testing of incremental changes gives you the opportunity to tweak elements of your website towards the proper purpose of a redesign: happier customers and better conversion.