I'm spending the next few months of Founder Log posts walking through the DCMA's 14-point schedule assessment, one check at a time, in plain language. Check #1 is Logic, and it's the simplest one to explain — which is exactly why it's first.
Every activity in a schedule should have two things: a predecessor (something that has to happen before it can start) and a successor (something that depends on it finishing). When an activity is missing one or both, schedulers call it an "open end." It sits in the network disconnected from the rest of the plan.
Why open ends are dangerous
An open end isn't just messy — it's a blind spot. If an activity has no successor, it can slip by weeks and nothing downstream reacts to it. The finish date doesn't move. The schedule still looks green. But the work behind it is actually late, and nobody's watching because the software isn't set up to notice.
I've seen this more than once in real schedules: hundreds of activities, a handful of them quietly floating free of the network, and nobody catches it until the work is already behind and there's no paper trail showing why.
Why this is check #1
Every other DCMA check — float, constraints, duration, all of it — assumes the network logic underneath is sound. If activities aren't properly linked, every other number in the schedule is built on a shaky foundation. That's why logic gets checked first, and why it's the first thing Ordo7 checks too: before it tells you anything else about your schedule's health, it tells you whether the logic holding it together is actually complete.
Next up in this series: Leads — what happens when an activity is allowed to start before its predecessor actually finishes.
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