A precedence diagram is a building block for more advanced techniques in operations and project management.  Precedence diagrams are used as inputs to PERT and Gantt charts, line balancing, and Critical Path Method (topics of future installments of “The Third Degree.”)
     Many resources discuss precedence diagramming as a component of the techniques mentioned above.  However, the fact that it can be used for each of these purposes, and others, warrants a separate treatment of the topic.  Separate treatment is also intended to encourage reuse, increasing the value of each diagram created.

     A cause & effect diagram is best conceptualized as a specialized application and extension of an affinity diagram.  Both types of diagram can be used for proactive (e.g. development planning) or reactive (e.g. problem-solving) purposes.  Both use brainstorming techniques to collect information that is sorted into related groups.  Where the two diverge is in the nature of relationships represented.
     An affinity diagram may present several types of relationships among pieces of information collected.  A cause & effect diagram, in contrast, is dedicated to a single relationship and its “direction,” namely, what is cause and what is effect.