tibi, are you listing different permutations of a “ghost schedule” ?

– “early”, “late” (and anything in-between) seen not as co-existing within one and the same schedule at any given point (initial baseline, regular progress updates) except the finally archived/ as-executed schedule), but considered, communicated and (gods of planning forbid!) maintained separately

– internal vs. client-facing parallel planning/ scheduling, the “double book-keeping” of project/ time management. say what you will, it’s much more common than a single source of truth, shared between all own organisation’s team members, various stakeholders, project teams/ contract parties

– various levels of (the) schedule, not properly integrated, not interfaced horizontally (same level, different teams/ contractors etc) and vertically not rolled up with lower (detailed) schedules not supporting the integrated master schedule, in turn supporting high-level overviews/ summaries and (key) milestone schedules.
sometimes maintained separately (at various granularity levels) within the same planning tool, more often with lower levels (day-to-day) schedules (term used loosely, here) maintained in a different (incompatible, preferable, scaled-down) planning tool, various spreadsheets, lists, mobile app, notebooks, flipcharts, napkins etc 🙂

shahid, you and derek have very valid points. i’ve tweaked the last part of the article to make my position on ghost schedules clear. i’m not an advocate, but am raising the issue for discussion and hearing comments such as yours. based on comments, it seems like clarity is paramount and that having simultaneous schedules is very likely to compromise clarity. fair?

derek, good points of course. let me be clear that i’m not advocating for their use, merely pointing out that they are out there. if they are used, then it should be in a mutually beneficial manner.