Plone is a powerful system that allows you to create complex sites, with complex workflows and user access control. But how do you know if the site you are building really does what you expect it to do? You have workgroups that can be private, public or secret; you have documents that can be private, draft, pending or published; you have users that can be members, authors, reviewers, contributors, managers... How can you be sure that for every combination your site does what you expect? I will present the experiences of developing a complex intranet with a scenario similar to above, and show the tools we developed and the approach we used to ensure that that policy as defined by the client was what the site eventually conformed to. We built a testing system to allow the policy for a site to be easily defined and the thousands of security permutations to be effectively visualised and problem patterns spotted. The talk will also include a step by step run through of the use of the tools and a simple example of testing site policy.