Microsoft Project Online is approaching retirement - or, in this case, its retirement date has already passed. But replacing a project management platform is not as simple as moving tasks from one product to another. In this episode of Support Engineering Weekly, Alex and Maya examine the architectural differences between Project Online and Planner Premium, and why treating Planner Premium as a one-to-one replacement can put important business processes at risk. We begin by separating project execution from enterprise project and portfolio management. Planner Premium is well suited to structured collaborative execution, including task dependencies, milestones, timelines, and critical paths. But enterprise workloads may also depend on resource capacity planning, complex timesheets, financial forecasting, and cross-project management capabilities that require a different approach. The discussion explores Planner Premium’s technical boundaries, including task, resource, custom field, successor link, and project duration limits. We then examine the illusion of equivalence: why workload visibility is not the same as enterprise resource management, and why portfolio views do not automatically unify every project management system. From there, we look at the hidden dependencies that make migrations difficult: Power Automate flows, custom Power Apps, APIs, reporting, financial systems, governance, and the need to establish an authoritative plan of record. Alex and Maya then walk through a fit-gap assessment approach, from identifying the business capabilities teams actually use to classifying requirements, validating dependencies, selecting the right destination, and testing complex workloads in a pilot. Finally, we explore how different workloads may need different destinations—including Planner Basic, Planner Premium, Project Server, Dynamics 365 Project Operations, Project desktop, or archival for inactive projects. The central lesson: Don't replace the product. Replace the capability. Disclaimer: This episode discusses the Microsoft Project Online retirement date of September 30, 2026, which has already passed. The episode is being published after that date because an earlier publication slot was not available. The discussion reflects the retirement timeline referenced during the original recording. Chapters 00:00 — The Retirement Deadline and the Assumption 02:01 — Project Execution vs. Enterprise PPM 04:35 — Planner Premium's Technical Boundaries 07:44 — Visibility vs. Resource Management 11:29 — Dependencies, Governance, and Migration Risk 17:12 — Routing Workloads to the Right Platform 20:01 — Archive What No Longer Needs a Home Learn more: The full technical article, references, and supporting resources are available through the Support Engineering Blog at https://blog.sadhan.ch/.