Planner answers

What is a fragnet in a Time Impact Analysis?

Short answer: A fragnet (fragmentary network) is a small set of activities and links that represents a delay event - for example late drawings followed by redesign. It is inserted into the programme current at the time of the event; the difference in completion date is the time impact of that event.

A good fragnet is simple, factual and traceable: each activity has a duration supported by records (the letter, the instruction, the approval date), and it is linked only to the activities the event really affected. Typical fragnet: Instruction issued → redesign by others → approval → resume affected work.

  • Insert it in the update with the data date just before the event.
  • Do not change any other logic or duration in the same run.
  • Report the unimpacted finish, the impacted finish and the difference.

Chronaxis inserts fragnets automatically for each event and gives you the impacted XER for the Engineer.

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