The nature of contracts generally being agreed price or percentage of work, the revenue is more or less is fixed irrespective of the time spent by the people and hence poses challenge for making decent profits. This may be further complicated by hiring of sub-contractors, consultants on different terms & conditions.
Eff Factor will be the right solution where its flexible budgeting feature as well as reporting of cost & revenue on on-going basis will be prove to be extremely useful. Feature of easy to add task makes it more relevant to this field where scope of the work may change frequently over a period of time.
Imaginative listing of task to capture time/cost etc. (for eg: redesigning arising from change in specifications by the client.) may help you in controlling the cost or seeking additional revenue.
Feature of estimate of Eff Factor allows a better control till completion of project as estimate itself is convertible into a project with required modifications.
(Please refer to Ideal Solution for other professionals/businesses also)