Using JIRA to estimate a project and then track against the estimate

[Sasha Klein]

I work (as an engineering director) at a design/dev company that does work for clients. 

Before starting projects, I'll estimate them out on a line-item level in a Google Sheet to get an accurate view of the time required. This sheet includes not only task-by-task estimates, but also our final proposed cost (hours multiplied by rates, differing by role), along with the ability to "buffer" estimates when design isn't clear, and to schedule them out over time.

Then we jump into the project, and start tracking work in Zenhub, a Kanban tool built on top of Github. 

The trouble is, we want to track our progress against our estimates as the project continues, but our Github "tickets" aren't generally one-to-one with the Google-Sheet estimate -- they're usually much finer grain. And then there's no automatic feedback from the Github tracker to the Google Sheet, as well as no built-in way to track how much time tasks took against how much time we estimated them to take (in the original estimate, or on the ticket). 

I'm looking for alternate workflows, and JIRA looked like a good alternative. Based on research on the tool, it looks like the ideal might be:

- Group line items as Initiatives (I already do this on my spreadsheet). 

- Each line item would then be an Epic, with a specific time estimate.

- As we start coding, we'd attach Stories to these epics, and the stories would have specific estimates as well. 

The hope would be that I could then track actuals (of stories) versus estimates (of Epics and of Stories), and keep better track of both A) How accurate the estimates were, and B) Where we stand on the schedule, and whether we're "on track". 

Is this workflow something Jira would support?

Does it have good tools for high-level tracking of total hours on a project? Could I plug in things like our rate or our start date (and any holidays or weekends) to calculate predicted end date?

If not, does anyone know of a tool that could handle all the above?

Thanks!