A project schedule can pass every DCMA assessment and still be unreliable.

It reflects a common misunderstanding in project controls: passing schedule health checks does not prove that a schedule is correct. It only demonstrates that certain quality criteria have been satisfied.

In mathematics, there is a concept known as a ‘Necessary but not sufficient condition’.

A necessary condition is something that must be true for a desired outcome to occur. If the condition is not met, the outcome will definitely be negative. However, satisfying a necessary condition alone does not guarantee success. Other conditions may also need to be met.

This distinction applies directly to project schedule validation.

A widely accepted rule of thumb is that every activity should have at least one predecessor and successor. While there are exceptions, this is generally considered good scheduling practice.

Having predecessors and successors is a necessary condition for a quality schedule. It is not a sufficient condition. A schedule may satisfy this rule completely and still contain missing dependencies.

This is not a criticism of DCMA assessments. They were never intended to prove schedule validity. Their purpose is to identify basic scheduling and performance issues. Problems arise when compliance scores are mistaken for evidence that the schedule is complete, realistic, and feasible.

Missing dependencies create unrealistic optimism. Activities appear able to start earlier than they can in reality, resulting in delivery dates that cannot be achieved. In a schedule, the absence of a single dependency can alter the resource-critical path and reduce project duration.  

Only one missing critical dependency may be enough to invalidate the entire schedule.

Technological dependencies, sometimes referred to as process dependencies, should not be identified from scratch every time a schedule is developed or reviewed.

A more mature approach is to develop a library of standardised work packages known as fragnets. Each fragnet represents a proven technological process with activities, sequencing logic, required skills, productivity assumptions, and constraints already analysed and documented. The project schedule is then assembled using these validated building blocks rather than creating logic relationships from scratch for every project.

By comparing a schedule with approved fragnets, planners can more effectively identify missing or inconsistent technological dependencies. 

This approach requires mature classification structures for activities, deliverables, and WBS elements. Without standardisation, meaningful comparison becomes difficult.

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