Maintenance module improvement

Hi everyone

I have some idea for maintenance module to improve it and want to list them here:
1. When a customer notified about a upcoming service he will ask someone who is in charge of this case to follow up service procedure, but it may takes some days to do the service because of many reasons (i.e. vehicle is in a trip). It would be so interesting if we have 2 steps for registering a maintenance service in Wialon. First step, after we notified we will register maintenance service request that means some one should start procedure of this service. in second step after service is done, user will register another event will finish it, enter costs and etc. In short each maintenance service should have 2 states, Requested and Done, only requested services will be listed for user to be done. In Reports we may have possibility to report Requested services and Done services and number of them.
2. Grouping/Categorizing services seems interesting as well (user can define these like this: Engine services, Suspension service, Body service and.. or any other type of categorizing). this way we can report on them and analyze each category/group for example when we check costs. 
3. We except improved maintenance module to give us an ability to enter amount of used parts in service beside costs when we registered it as done. A metric should be defined for each service (maybe when we define service itself or when we register it as done).
4. We may have a possibility to enter Technician name and  beside Location.
In case we add these functions to Maintenance module then we should add some tables, column or abilities in reports concerning about:
A. Grouping services based on services categories and number of them
B. Description of each requested/done service in reports
C. Grouping services based on technician who did it
D. Reports on services based on service states (requested/done)
E. Costs, Duration, amount of used parts in total and in details based on grouping options in table properties
F. A column for User who is requested or registered the service as done

Valuable partners please share ideas...