In a project network, a dependency is a link amongst a project's terminal elements. A project network is a graph (flow chart) depicting the sequence in which a projects terminal elements are to be completed by showing terminal elements and their dependencies. ... A project is a temporary endeavor undertaken to create a unique product or service. ... In project management, a terminal element is the lowest element (activity or deliverable) in a work breakdown structure; it is not further subdivided. ...

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

1. Finish to start (FS)
   • A FS B = B doesn't start before A is finished
   • 
   • (Foundations dug) FS (Concrete poured)
2. Finish to finish (FF)
   • A FF B = B doesn't finish before A is finished
   • 
   • (Entire book written) FF (Last chapter written)
3. Start to finish (SF)
   • A SF B = B doesn't finish before A starts
   • 
   • (New shift started) SF (Previous shift finished)
4. 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:

1. Causal (logical)
   • It is impossible to edit a text before it is written
   • It is illogical to pour concrete before you dig the foundations
2. Resource constraints
   • It is logically possible to paint four walls in a room simultaneously but there is only one painter
3. Discretionary
   • 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. Resources comprise the base material for an activity or industry: See resource (economics) for the term as used in economics See human capital for human resources (HR) and innovation See natural resources for material matter See resource (computer science) for the computer science meaning of resources This is a disambiguation... A constraint is a limitation of possibilities. ... The term may refer to Critical path -- a notion from project management Critical Path (book) by Buckminster Fuller This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... For schedule in computer science, see schedule (computer science). ... In project management, the critical chain is the sequence of both precedence_ and resource_dependent terminal elements that prevents a project from being completed in a shorter time, given finite resources. ...

See also

• dependency injection
• list of project management topics
• project network
• project planning