Rearchitect existing code

Rearchitecting code such that functionality of current application can be offered as individual components/modules. Existing pertains to a web application written in PHP/Code Igniter. It offers several different categories/modules of functionality. Such as CRM, Testing, Forums. Users had access to this functionality. Now objective is to create more categories of users, such that modules can be assigned or offered to these categories. The new application would be offered as a SAAS service. Customers can select modules - e.g. only CRM or CRM and Forums, only Testing. At this stage no additional features or functionality is planned to be added. That would be a second phase activity.