Security stretegy for a cloud applicaion

<br> I am developing an applicaion for different small scale industries. Each industry can create its project in it and provide users and roles.&lt;br&gt;<br> &lt;br&gt;<br> For each company, role based security can be implemented. But I don't know how to implement it on the fly when a new company profile is created. The security should be as of salesforce. We can have mutliple organizations in one project but each organization implements<br> has its own role based security.&lt;br&gt;<br> <br> i m using asp.net mvc 4.<br> &lt;br&gt;<br> please help me on this.<br>