Predecessor / Successor

What must be finished before this, and what waits on it — the dependency relation the whole plan rests on.

Two words, one relation, written both ways. Every row of The activity table names what comes before it and what comes after, so the network can be read forward or backward by hand. Forward it says when a thing can start; backward it says how late it may be. Everything computed about a plan — Critical Path, Float, the finish-by dates that make a promise honest — is computed from nothing but durations and these links.

It is load-bearing because a dependency is the only thing a plan knows that a list does not. A list of work in date order hides the question that decides everything: what do you need from me, finished, so you can start? Pull planning exists to surface exactly that, and the answer, once given, becomes a link in the network and a handoff between two people. The successor is the customer, and the handoff is where systems fail — which is why the link carries Conditions of satisfaction with it and not merely an arrow.

It is also the relation that federates. A Cell's activity may have a supercell's milestone as its successor, or another Cell's deliverable as its predecessor; agreed in both directions, those interface links are how separate plans become one plan without anyone owning all of it. An activity with no successor serves nothing; an activity with no predecessor can start today.

Also called: dependency · what comes before and after Stands on: The activity table · Pull planning Opens onto: Critical Path · Float · Conditions of satisfaction · The plan of the whole In play: table · beyond Sources: The LIØNSBERG Lexicon (Work In Progress) §The System, which names Predecessor and Successor beside Network of Commitments and Pull Planning · The LIØNSBERG Operating System (book, draft v0) §4 · Activity and Float (wiki term pages, drafts, unreviewed) — lionsberg.wiki page name: Predecessor Open: The Lexicon lists the pair without defining it; the definition above is gathered from the planning drafts. · Name: the / in this concept's name is written as a hyphen in this page's filename.