{"id":6211,"date":"2022-03-08T10:14:02","date_gmt":"2022-03-08T10:14:02","guid":{"rendered":"https:\/\/www.nimblework.com\/knowledge-base\/nimble\/?post_type=article&p=6211"},"modified":"2025-07-27T09:31:29","modified_gmt":"2025-07-27T04:01:29","slug":"task-dependencies","status":"publish","type":"article","link":"https:\/\/www.nimblework.com\/knowledge-base\/nimble\/article\/task-dependencies\/","title":{"rendered":"How Task Dependencies Impact Project Schedule"},"content":{"rendered":"

This article provides valuable insights into task dependencies and outlines the steps to link and delink tasks in advance scheduling.<\/p>\n\n\n\n
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Skip Ahead to:<\/strong><\/p>\n

Overview<\/a><\/p>\n

How do Task Dependencies affect the Project Schedule?<\/a><\/p>\n

Steps to Link Tasks<\/a><\/p>\n

Steps to Remove Links<\/a><\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

<\/a>Overview<\/h2>\n

The predecessor is the activity whose start or finish affects the start or finish of another activity. \u00a0The successor is the activity whose start or finish is dependent on the start or finish of another activity.<\/p>\n

For example, you need to paint a wall but before that, you need to apply the primer to the wall. This means the activity \u201cpainting the wall\u201d can be done after the activity \u201capplying primer on the wall\u201d. So \u201capplying primer on the wall\u201d is the predecessor activity while \u201cpainting the wall is the successor\u201d activity which depends on the finish of the former activity.<\/p>\n

Note:<\/strong> The Task Dependencies option is only available in Advanced Scheduling.<\/p>\n

<\/a>How do Task Dependencies affect the Project Schedule?<\/h2>\n

Task links show the relationship of tasks with one another in time. The linking of tasks is also called Task Dependency. When you link tasks, a chain of tasks is set up. The long chain of tasks helps you decide the length of the project as well as the project end date.<\/p>\n

Task Dependency is important as it impacts the project schedule. When you make any changes to a predecessor, it affects the successor which further affects the next successor, and so on.<\/p>\n

Note:<\/b>\u00a0When you set links between tasks (define task dependencies), the project creates a critical path of the links. This critical path helps you determine the finish date of your project. Read more about the critical path from\u00a0this page<\/a>.<\/p>\n\n\n\n\n<\/colgroup>\n\n\n\n\n\n\n
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Link<\/strong><\/p>\n<\/td>\n

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Example<\/strong><\/p>\n<\/td>\n

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Description<\/strong><\/p>\n<\/td>\n<\/tr>\n

<\/a>Finish to Start<\/td>\n\"\"<\/a><\/td>\nIn the finish-to-start dependency, the dependent (successor) task (B) doesn\u2019t begin until the task on which depends (predecessor task) (A) completes.<\/p>\n

For example, you need to prepare a presentation and show it to your manager. In order to show the presentation, the presentation must be prepared. So the activity \u201cshowing presentation\u201d cannot begin until the activity \u201cpreparing presentation\u201d is done. Here \u201cpreparing presentation\u201d is the predecessor and \u201cshowing presentation\u201d is the successor.<\/td>\n<\/tr>\n

Start to Start<\/td>\n\"\"<\/a><\/td>\nIn the start-to-start dependency, the dependent (successor) task (B) doesn\u2019t begin until the task on which it depends (predecessor task) (A) begins.<\/p>\n

For example, you need to create a user manual and add the relevant images\/screenshots to it. Here the activity \u201cadding screenshots\/images\u201d cannot begin until the activity \u201cwriting user manual\u201d begins. These two activities can go parallelly and thus these are start-to-start activities. Here \u201cwriting a user manual is the predecessor \u201d and \u201cadding screenshots\/images to it\u201d is the successor.<\/td>\n<\/tr>\n

Finish to Finish<\/td>\n\"\"<\/a><\/td>\nIn the finish-to-start dependency, the dependent (successor) task (B) doesn\u2019t complete until the task on which it depends (predecessor task) (A) completes.<\/p>\n

For example, consider a scenario where one needs to write code for a module and do the unit testing of the code. Now the activity \u201cunit testing of the code\u201d cannot be completed until the activity \u201cwriting code for the module\u201d is completed. Here \u201cwriting code for the module\u201d is the predecessor and \u201cunit testing of the code\u201d is the successor.<\/td>\n<\/tr>\n

Start to Finish<\/td>\n\"\"<\/a><\/td>\nIn the start-to-finish dependency, the dependent (successor) task (B) doesn\u2019t complete until the task on which it depends (predecessor task) (A) begins.<\/p>\n

For example, consider a scenario where two guards – morning and night guards are posted on duty. Now the duty of the night guard cannot finish until the morning guard starts his duty. Because he (nightguard) cannot leave the post vacant until the other guard joins. Here \u201cduty of the night guard\u201d is the successor and the \u201cduty of the morning guard\u201d is the predecessor.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Note:<\/b> The manually scheduled tasks are driven by the dates defined by the user and not by the dependencies defined on them. For example, if a predecessor manual task has a planned start and planned finish date and 1 January and 5 January and its successor manual task with FS dependency has a planned start and finish date of 6 January and 12 January. Now, if the predecessor task finishes on 7 January instead of 5 January then too, the successor task will start on 6 January and not on 8th January (as per dependency).<\/p>\n

<\/a>Steps to Link Tasks<\/h2>\n

You can link tasks (set dependencies between tasks) within a project. Once tasks are linked, changes made to a predecessor task automatically affect its successor, which in turn can impact its own successor, and so on.<\/p>\n

To link tasks:<\/p>\n

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  1. \n

    Open the Task Plan in the task listing view and select the task.<\/p>\n<\/li>\n

  2. \n

    In the Predecessor<\/strong> column, enter the dependency in the following format:
    <Task ID> <Dependency Type> \u00b1 <Lag\/Lead><\/code>
    For example: 12FS+2<\/code> or 14SS-1<\/code><\/p>\n<\/li>\n<\/ol>\n

    For example, if you want to set Task2 as the predecessor for a task with the start-to-start dependency, then you need to write 2SS. Here 2 is the task ID and SS is the start-to-start dependency. Now, if you want to add 3 days lag between the predecessor and successor task, then you can write – 2SS+3.<\/p>\n

    Note:<\/b> You can also define the task dependency in the Gantt chart view by simply dragging the pointer from the predecessor task to the successor task. By default, it will create the finish-to-start dependency in the Gantt view. You can create only FS dependency in the Gantt view, however, all types of dependency are visible in the Gantt view.<\/p>\n

    \"Link<\/p>\n

    You can also define the dependency type in the Detail view of a task. In Advanced Scheduling, dependencies can be set for summary tasks as well.<\/p>\n

    Important:<\/b> If task A is linked to task B and task B is linked to task C, then task C cannot be linked to task A as it creates circular dependency which is not allowed in Advance Scheduling. In this case, the project notifies the user about the circular dependency and shows a message on the screen.<\/p>\n

    <\/a>Steps to Remove Links<\/h3>\n

    To remove task links (dependencies) in a project:<\/p>\n

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    1. \n

      Open the Task Plan in the task listing view and select the task whose link you want to remove.<\/p>\n<\/li>\n

    2. \n

      In the Predecessor<\/strong> column, clear the dependency values.<\/p>\n<\/li>\n

    3. \n

      Click outside the cell to apply the change. The task dependencies will be removed automatically.<\/p>\n<\/li>\n<\/ol>\n

      Note:<\/b>\u00a0You can\u2019t remove the dependencies from a task from the Gantt chart view.<\/p>\n

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