Over time, the rules for calculating public utility services can change. In the program, they stored with an indication of the validity period. For example, in 2009, the accrual of water was carried out based on the number of people. Since January 2010, the calculation based on the consumption volume calculated based on the consumption rates. Two different procedures are used to account for this service. Depending on the period for which the calculation made, the procedure works. This approach ensures the identity of the calculation results when performing recalculations for previous periods.
The program allows you to configure accounting for a specified set of services by using prototype services or developing programs for calculating and the number and cost of new services. The simplicity of developing such programs was initially one of the technical requirements for the system. The implementation allows the maintenance the programmer to not be engaged in a routine of preparing the initial data for calculating the quantity and cost and placing the calculation results in the database. All this is solved at the system level, leaving the programmer only the part that relates to the new service.
The structure of the service parameters, their display in the reception window, access protection service and its separate parameters is solved by system means.
