Universal planning errors: from a typology to a working tool for the project manager

This article is devoted to universal mistakes of planning, that arise during the work on a project. Inconsistencies between project planning documents arise in the first days of a project and recur regardless of industry, scale or planning technique, yet stay invisible when a document is read alone: each follows its own rules, while the inconsistency lies between them and requires a rarely mandated cross-check. The aim of the study is to build an analytical frame for reading a set of planning documents along three dimensions — technical, user and commercial and turns it into a working tool for project managers. The frame is derived from the three IPMA ICB 4.0 competence areas and the three PMI Talent Triangle categories and is claimed as an original development. The empirical base of the study is twenty team sets of planning documents from two master’s cohorts: the typology was built on the ten 2026 sets and tested independently on the ten 2025 sets, collected a year earlier. Seven universal errors are identified with their degree of impact. The two cohorts showed similar errors; four of the seven occur in at least seven sets of each. The cost estimate diverges from the other documents in two opposite ways, depending on whether a numerical budget limit is stated. The frame becomes a checklist separating machine checks from the project manager’s decisions.