Dependency (project management)

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In a project network, a dependency is a link amongst a project's terminal elements.

There are four kinds of dependencies with respect to ordering terminal elements (in order of decreasing frequency of use):

Finish to start (FS)
* A FS B = B doesn't start before A is finished
*
* (Foundations dug) FS (Concrete poured)
Finish to finish (FF)
* A FF B = B doesn't finish before A is finished
*
* (Entire book written) FF (Last chapter written)
Start to finish (SF)
* A SF B = B doesn't finish before A starts
*
* (New shift started) SF (Previous shift finished)
Start to start (SS).
* A SS B = B doesn't start before A starts
*
* (Project work started) SS (Project management activities started)

There are three kinds of dependencies with respect to the reason for the existence of dependency:

Causal (logical)
* It is impossible to edit a text before it is written
* It is illogical to pour concrete before you dig the foundations
Resource constraints
* It is logically possible to paint four walls in a room simultaneously but there is only one painter
Discretionary (preferential)
* I want to paint the living room before painting the dining room, although I could do it the other way round, too

Traditional critical path-derived schedules are based only on causal (logical) dependencies. The critical chain method necessitates taking into account resource constraint-derived dependencies as well.

Dependency (project management)

See also