Before you begin defining routing tasks and assigning sub-tasks, you need to establish the work flow of the main task. In other words, can the task be completed with a linear approach or are there several simultaneous steps? It may help to diagram the work flow (see the example below).
If you have simultaneous steps, you can assign the same step number to multiple tasks, resulting in more than one "pending" task at a time. You can also assign the same prior step to multiple tasks. Since the prior step number determines the sequence in which tasks can be closed, use caution when assigning prior steps to preliminary tasks (i.e. the prior step must be closed before you can close the current task).
Example
The main task is Install new street. Before a crew can physically install the street several other events or actions must occur; these are the routing tasks. Each routing task is described below along with a diagram.
Step 1 might be Present to Council. The prior step would be 0 since this is the starting task. Once this step is completed, step 2 will be activated.
Step 2 would be to Install Temporary Signs with a prior step of 1. Once this step is completed, step 3 will be activated.
Step 3 would be Survey, with a prior step of 2. Once this step is completed, step 4 will be activated.
Step 4 would be the actual Physical Installment of the road. At the same time, you might also need to get the street naming and addressing process started. So you would have two steps marked as step 4. However, each would have a different prior step number. For step 4 - Install Street, the prior step would be 3. For step 4, Submit Street for Naming and Addressing, would have a prior step of 1.
Step 5 (the final step) would be to Install Permanent Street Signs. The prior step would be step 4, which means that BOTH steps marked as step 4 need to be completed first (e.g. the street name must be approved and the street must actually be built before permanent signs can be installed).