DTV12 — ad-hoc time tables reference the same situation kind for all the time table entries

Experience with FIBO reveals two problems with the way schedules are defined in DTV:

1. DTV schedules that are based on ad-hoc time tables reference the same situation kind for all the time table entries. This is a problem because financial contracts that use ad-hoc time tables need to specify a unique situation kind for each entry.

For example a step-up bond pays different interest rates for different periods. An ad-hoc time table can adequately represent the different periods, but each interest rate needs to be a distinct situation kind – which is not possible in the current design.

The RTF agrees with the problems raised by these issues. Their resolution requires reworking both the DTV ‘schedule’ and ‘time table’ concepts, because:
• The time table concept was created to support the schedule concept but it does not properly support the business concept of ad hoc schedules. As defined, there are two kinds of ‘time table’ (‘regular’ and ‘ad hoc’) and one kind of ‘schedule’ that has a single general situation kind.
• What is needed is two kinds of ‘schedule’, one of which associates a single situation kind with a regular time table, and the other associates multiple situation kinds, each with its own time period.
• Also, the existing ‘regular time table’ is defined as a set of time periods, when what is really needed is a starting time, a repeat count, and a repeat interval.
To solve these problems, the RTF is forced to entirely replace the original ‘schedule’ design.
The resolution of issue 19653 is merged into this solution because the two issues are intimately connected. This resolution adds the ‘schedule stub’ idea.
A verb concept 'time interval1 starts after time interval1' is added to clause 8.2.4 to simplify the definition of 'schedule has earliest time'.
A synonym is added for DTV ‘situation kind’ to match the designation of the equivalent concept in FIBO.
A verb concept "set1 is set2 plus element" is added to a new Annex D.2.6 to support the definition of regular schedules.