Pick a Scenario, Then What?

Now that I have enough of a scenario.  What do I do next?  I could create a screen (or page).  I could create classes for some of the domain objects.  I could create the back-end service that will talk to the DB and provide the information for the page.  

Here's perhaps a better question: How do I tell when the scenario is complete?

Well, perhaps the easiest way to proceed is to create a list of tasks.  When the tasks are done, the scenario is complete.  

Task List

So, with this in mind, here is the list of tasks:

1. Create a "Start Page" to launch the "Create a New Group" page. DONE
2. Simulate user information on this start page. DONE
3. Create the "New Group Page". DONE
4. Get user from context. DONE
5. Add name input. DONE
6. Add location input. DONE
7. Add description input. DONE
8. Add public/private flag input. DONE
9. Add create button. DONE
10. Create back-end service
11. Add CreateGroup method to back-end service
12. Add CheckGroupName to back-end service
13. Add CheckCity to back-end service
14. Create Group class
15. Create User class
16. Create Invitee class

Other Tasks

I am sure that I'll think of other tasks as I go through these tasks.  Those will just need to be added when they come up.

Estimates

Part of the process of developing software is to give an estimate of how long something is going to take.  This is generally a tricky business, that is, it is hard to get it right.  Why is this the case?  Partly because the nature of a task is not completely understood.  Partly because other things come up.  Partly because the task changes.  Partly because things that the task depends on changes.  

The Backlog

So, what can be done about this tricky stuff?  One thing that I like is the idea that a task is in one of 3 states -- done, in process, or back logged.  Things that get done count.  Really only one thing is in process at a time.  Everything else is in the backlog.  

If something in process is blocked, it goes back into the backlog until it can be unblocked.  It gets unblocked when whatever it depends on is done.  If it is blocked by something that was unknown, a new tasks is created and added to the backlog, moved to in process when it is the thing that is in process, and then on to the done stuff when it is done.

But not of this fixes the estimate challenge.  Each task still needs to be estimated and then measured and then the actual is compared to the estimate.  This shows how close the original estimates were and allows for better predictions when subsequent tasks are estimated.

The First Estimate on This Project

Well, I'm going to tackle the "create a start page" task.  I happen to have 15 minutes, so I'm going to give that as my estimate.