Every project is built using tasks and they can be interrelated.This interlinking is called Task Dependency in Zoho Projects.

What happens when you set dependency?

The task for which you set the dependency will become your parent task and the task that depends on your parent task is the child task. According to our Finish to Start design, only if you complete your parent task, you can start your child task. Check out our tip to understand dependency.

How to?

1. Navigate to Projects and click the drop down in the left corner.
   
2. Select Project Templates.  
   
3. Click the particular template and select Tasks in the left menu. 
   
4. Select Add Task to create new tasks.
   
5. Click Dependency View and start setting dependencies for your tasks.

What if you have a similar set of tasks for the upcoming projects?

Setting dependencies every time you create a project is time-consuming. To solve this, you can set dependencies from within a project template. Now, you can create 'n' number of projects with the same set of tasks and dependencies by just picking the existing templates.

Use case

Here's a business scenario that helps you understand better how dates function using dependency.

Helen creates a project template 'Content Requirements' where she adds all the tasks that are required for creating a new product.  

While creating dependencies in Project templates, instead of defining the start date and end date, you set the Start After and Duration.  When you call the template in any project, the dates of the tasks are defined based on the project's start date. There is no End Date concept when you define dates for your tasks in project templates.

Start After: A defined number of days/hours after the project start date when your task can start. 

Duration: The days required to complete the task.

Predecessor: The parent task on which your current task is dependent on.  And, it is the place where you set dependencies for your tasks. (For example - You have two tasks: 1 and 2. If you set task 1 as a predecessor for task 2. Then you can start task 2 only after you complete  task 1).

Case 1:

For the task 'Welcome Home Screen', the dependent task is 'Design Home Screen'. She adds the predecessor number for the task 'Design Home Screen' and thus the parent task will be 'Welcome home screen' and the child task will be 'Design home screen'.

Project start date: 4/19/2017

This is the dependency view in project template

'Welcome home screen' start date: 4/21/2017 (Starts after 2 days and runs for 4 days)

'Welcome home screen' end date: 4/26/2017

'Design home screen' start date: 4/28/2017 (Starts after 7 days and runs for 5 days)

'Design home screen' end date: 5/04/2017

When you choose the above template in your project, you can see the Start date, Due date, and Duration based on the Start After and Duration that you mentioned for the tasks in your template. 

Positive case:

The child task starts only after the parent task ends (Finish to Start model). Now, Helen will complete the 'Welcome Home Screen' task and then start the 'Design Home Screen' task.

Case 2:

For the task 'Product help', the dependent tasks are 'Help tour' and 'Page tips'. She adds the 'Product Help' as the predecessor for task 'Help Tour' and 'Page Tips'. Here, the parent task is 'Product help' and the child tasks are 'Help tour' and 'Page tips'.

Project start date: 4/19/2017

'Product help' start date: 4/21/2017 (Starts after 2 days and runs for 5 days)

'Product help' end date: 4/27/2017

'Help tour' start date: 4/25/2017 (Starts after 4 days and runs for 3 days)

'Help tour' end date: 4/27/2017

'Page tips' start date (Page Tips): 4/26/2017 (Starts after 5 days and runs for 1 day)

'Page tips' end date: 4/26/2017  

An error message is displayed when the task dates conflict. Now, you need to set the dates accordingly to troubleshoot this error.

Negative case:

Both the child tasks start date is earlier than the parent task's end date. The Finish to Start scenario fails in this case, so Helen will not be able to set dependencies for the tasks. She has to changes the Start After days for the child tasks to fit in the end date of the parent task.

Can I set Start After and Duration only in days?

You can set the Start After in days, weeks, months, and hours and the Duration only in days and hours. Based on the defined Duration and Start After days, the dependencies will follow the Finish to Start method.

What happens when I change the Start After days and duration of my parent task or child task?

While working on the tasks, you might sometimes feel that the respective task needs a day or two to complete. So, you tend to change the Start After or Duration of the parent task or the child task. In this case, your Start After and Duration of your tasks change automatically according to the extra days.

Can I add multiple dependencies?  

Yes, you can add multiple dependencies for your tasks. Every task has two or three dependencies to complete the main task. For example, Helen creates another three tasks in the template and then she sets multiple dependencies for those tasks.  

Project start date: 4/19/2017

This is the dependency view in project template

Now, she sets two tasks 6 and 7 as the predecessors for 8 and 6 as the predecessor for 7 respectively. So, only after task 6 completes, you can start task 7 and only after task 6 and 7 complete, you can start 8. Overall, task 6 is the parent task for task 7, and tasks 6 and 7 together are the parent tasks for task 8.

Integration task - Start date: 5/01/2017 (starts after 8 days and runs for 5 days)

End date: 5/05/2017

Error and alert message - Start date: 5/09/2017 (starts after 14 days and runs for 3 days)

End date: 5/11/2017  

Use cases - Start date: 5/15/2017 (Starts after 18 days and runs for 10 days)

End date: 5/26/2017

When you choose the above template in your project, you can see the Start date, Due date, and Duration based on the Start After and Duration that you mentioned for the tasks in your template. 

Can I set dependencies for subtasks?

Yes, you can add a subtask as a dependent to your parent task and vice-versa. The same 'Finish to Start' method works here. If you set a subtask as a dependent to your parent task, then your subtask should start only after the parent task ends. And, if you set a parent task as dependent on your sub-task, then your parent task should start only after the subtask ends.  

Click here to view business scenarios that will help you understand Task dependency.

Regards,

Monica.