Typically Scope Creep affects all kinds of projects.
This can be solved in many ways.
For every project, the basic clarity should be there in the requirements. Written and well documented.
Such strong conviction, of not going overboard on required, will cut down cost over runs.
Any creep of requirements ( customers will always try to add new requirements, after signing the project dev. ) should be well documented and charged. Certain companies I have worked with have the policy of charging ( change management ) only if there is excess of effort > 10% expended, as there is always a buffer of 10% added in the initial quote.
I was reading an article now Managing Project Profitability and some points are well written, that can be used in any typical IT project implementation ( & management ).