The cost of the resource in activity assignment?

As work was initialiy planned to store 'day' based work, database format was designed to restrictively as number(3,2).
Just change the format of "work" in the "work" table will correct the issue, for instance to number(5,2).

This will be included in V1.6.

You are still facing the bug #308, leading to error calculation of left work (and so planned work).
To correct it, you must do the following :
- modify de Assignment of "Fred Lin" with no function (the first line) : click on the pencil icon
- set a function to this assignment : the daily cost should automatically update
- save the changes to the assignement
- go to the "real cost allocation" and update a value to force recalculation of left work.
This must be done to each Assignment with no function.

No, you cannot change "Resource" and "Function" in the assignment when real work exists on the assigment.
But you can change cost of the resource for the fonction.

For instance, you start your project whith resource A at 100$.
You add assignments for this resource and he starts working : so he inputs real work, giving real cost. OK.
Next month, resource A get a pay rise (he's a good worker) and his cost is now 110$ for the same function.
You just have to enter the new cost for the resource / function, with the good starting date (let's say date D).
If the resource A has entered some cost on dates between date D and current day, the real cost is automatically updated.
The left cost (and planned cost), is also updated, taking into account the new cost.

I hope I was clear.