Which dependencies are legally mandated or involve logical sequences of tasks?

Mandatory dependencies are critical because they are legally mandated or involve a logical sequence of tasks that must occur in a specific order. These dependencies arise from the nature of the work being performed, as certain tasks cannot start until others are completed due to legal, regulatory, or logical requirements.

For example, in construction, you cannot start framing a building before the foundation is laid; the foundation task must precede the framing task. This legal and logical framework ensures that projects follow necessary guidelines, reducing the risk of errors or compliance issues.

While other types of dependencies exist, such as discretionary dependencies - which are based on preference rather than necessity - or concurrent activities - which can occur simultaneously when not dependent on each other, they do not carry the same weight of enforceability or sequence necessity as mandatory dependencies do. This makes it clear that mandatory dependencies are fundamental in establishing project timelines and maintaining operational integrity.