Dependency
A dependency links two tasks and sets their order. The most common case: finish-to-start – a task begins only once the previous one is complete. The plan thus reflects the real construction sequence.
Types of dependency
- Finish-to-start: the successor starts after the predecessor finishes.
- Start-to-start: both tasks begin together.
- Finish-to-finish: both tasks end together.
Dependencies in the construction sequence
In building construction many sequences are not a matter of preference but of technical necessity. Anyone who knows them spots an unrealistic schedule at a glance:
- The main contractor only starts in the excavation once earthworks are complete.
- Completion of the structure marks the start of building services.
- Work on the building envelope can only begin once formwork has been struck.
- External works only start once the scaffold is gone.
In the fit-out the order is particularly tight: base plaster to ceilings, then tiling, then the first ceiling coat with inspection, then parquet, followed by joinery and kitchen installation, appliances and finally painting. Swap them around and one trade damages the work of the one before.
Waiting periods are dependencies too
Not every dependency is an activity. A screed has to dry before the covering goes down; a component measured on the finished structure needs its production time. Such periods belong in the schedule as tasks of their own – otherwise the link looks sound while the date is out of reach.
In Menira you draw a dependency as a link between two bars. If a task moves, the linked dates adjust with it.