Work starts upon receiving inquiries (via email) from clients.
After the initial studies on the received inquiry we will list our questions to clarify the obscurities and will receive client's answers.
These sessions of Q&A.s may repeat several times in order to reach an acceptable level of clarity in all the grounds.
In the next step, cost and time schedule will get submitted to clients and upon receiving their confirmation, the work will commence. 
In case there would be any change demanded by clients, similar cycle will be in place till the entire work is successfully handed over.