The widespread use of eCommerce and mobile apps have forced ERP and CRM applications to add those capabilities. Unfortunately, legacy ERP platforms are often incapable of easily adapting to these new requirements. For some legacy providers, their solution is to offer cumbersome add-ons, sometimes with standalone databases. Others respond by taking old, legacy applications and adding additional software to the front-end to make their last generation software appear to be cloud applications.
In other instances, hard coded interfaces are created that break instantly when one of the two systems are upgraded. None of these are efficient, long-term solutions. A true cloud and mobile system is designed differently than a typical legacy client/server system.