Khal Khaireddin Architects - Internal Project Management Tool

I'd like to develop a way to more accurately manage and track the time spent on the architecture projects that we have in the office. We currently develop an estimate for the number of hours for each project in excel, and then use an online software called ArchiOffice Online to track our time and send invoices, but there's a disconnect between the estimated hours for each task, vs. how much time is spent on each task, and I'l like to close that disconnect and also have some other functionalities such as forecasting of our hours and budgets.