I have just released an activity module called Focuspad that I think may do what you require as a work log.
You can have a look at a demo and find out more at http://focuspad.mintranet.com.au
To account for the work ethic grade I would use a scale and set the grading to be cumulative within the activity.
I would also set it to use a template to help guide the students a bit.
If it would require any other features or modifications to be more useful let me know and I may be able to implement them.