In short
Planisware, Planview, Jira Align and Smartsheet are planning and portfolio platforms: they hold the plan across programs, the capacity, the budgets and the dashboards, and they are good at it. Tymeline is not an alternative to them. It is the always-on layer above the engineering tools that holds one program to its date and acts when a commitment moves. Companies that need portfolio governance keep the platform; the ones that need the date held add Tymeline.
Where each is strong
Planisware is the strongest choice for R&D portfolios with stage gates and resource planning. Planview is built for governance across many programs and investments. Jira Align lifts engineering work in Jira to a portfolio view. Smartsheet is quick to set up and good at dashboards and reminders. All four describe the program as people have entered it.
Where Tymeline is different
Tymeline does not wait to be told. It reads Jira, source control, EDA regression and coverage, PLM, ERP, the test floor and the supplier mail, and holds every commitment on the program against that evidence. When one starts to move, Kendrel works out the fix and the AI Employees carry it out within the authority they have, with a named approver for anything consequential. Every action has a signed receipt. The date is held rather than tracked.
Running both
The normal arrangement is both: the portfolio platform for the view across programs, Tymeline for each program that must land on its date. Tymeline can feed the platform the true state so the dashboards stop being a week old. Pricing is per program, never per seat, so adding it to one program does not mean a company-wide decision.