Subtasks may be changed using Change Properties just like other tasks. What can be changed depends on the state of the subtask. Note that subtasks of a main task in processing are automatically started when all input data are available. In this state, not all changes are possible and you have to withdraw the task request in order to be able to change the subtask. The action form for changing subtasks is the same as for creating subtasks.
When changing main tasks, i.e. task that have already subtasks, three additional form fields appear which relate to data coming from, or needed by, subtasks and conditions concerning their execution.
• Data needed by subtasks: Here you can select from input data fields of subtasks. By selecting such a data field you declare it as input field of the current main task. When the main task is started, the data field is released and is then available for the contractors of the subtask as input data.
Normally you would proceed top-down when linking data fields of main and subtasks, i.e. you would first define the input data of the main task and then declare these input data as input data of subtasks, if necessary. Here you have the possibility to do the same thing bottom-up: declare subtask input data, which are not supplied by other subtasks, as input data of the main task afterwards.
• Conditions for finishing the task: Here you can determine that the current main task may only be finished, when certain subtasks have been finished. Select one or more of the conditions offered.
<output of subtask released> means that the subtask has been carried out, hence is in a state where the output data cannot be changed (e.g. finished or accepted).
• Data coming from subtasks: Here you may select from output data fields of subtasks. By selecting such a data field you declare it as output field of the current main task. When the subtask has been finished and the data field is released, it is available as output data field of the main task. Here again you have the possibility to proceed bottom-up when linking data fields of main and subtasks: declare output data of subtasks which are not needed by other subtasks as output data of the main task.
If a given task is a subtask of a main task, has peer tasks as well as subtasks of its own, changing input and output data can require a rather complex form: apart from defining new input and output data, you can select from data and conditions concerning the main and peer tasks as well as from data and conditions concerning the subtasks.