How can I make sure a task can't be completed until its defined predecessor is completed?


  • Julio S.
    Julio S. Moderator

    Hi @dgorn,

    Although there is no direct way for you to lock specific cells based on other cells values. You could possibly implement an additional Checkbox column to help identify whether the predecessor has been completed or not for that row. 

    For the formula below to work, you will need to create an additional column in your sheet that contains a manual copy of all values in the predecessors column (Numeric value in my example below) and use the following formula: 

    =IFERROR(IF(AND(Predecessors@row <> "", INDEX(Status:Status, [Numeric value]@row) = "Complete"), 1), "")


    I hope that this solution can be of help for what you are trying to achieve