Construction Management Scheduling Software

Construction scheduling software is a narrower category than construction management software, and mixing them up is the usual reason a purchase disappoints. One runs the programme: activities, durations, dependencies, float, and what happens to the finish date when the steel arrives late. The other runs the project: drawings, RFIs, submittals, daily reports, and payment applications.

We sell source code you clone and run yourself, so there is nothing here to log into. Nobody should build a CPM scheduler, and this page is mostly about how to choose one and where the free options genuinely reach.

Critical path is a calculation, not a chart

The reason Primavera P6 keeps appearing in this search is that it implements the critical path method properly, and many cheaper tools draw Gantt bars without doing the underlying passes.

This matters commercially, not just technically. On a contract with liquidated damages, an extension of time claim is argued on the schedule, and that argument requires relationship types, lags, and a defensible baseline against which progress is measured. Tools that cannot express a finish-to-start relationship with a lag, or cannot hold a baseline separate from the live programme, cannot support that conversation.

What separates the tiers

The last row is the practical trap. A full CPM programme with two thousand activities is not a document a site foreman uses. What the site uses is a lookahead, usually three or six weeks, filtered to the trades working now. If the tool cannot produce that view, somebody rebuilds it in a spreadsheet every Friday, and the two versions drift.

Where the free options reach

For a small builder running a handful of jobs, the honest ceiling is higher than vendors suggest. If the programme is under about a hundred activities, dependencies are mostly finish-to-start, and nobody is going to litigate the finish date, a spreadsheet with dates and a simple Gantt tool covers it. Several free and low-cost tools handle this band well.

The point to move up is specific: a contract with liquidated damages, a programme where resource conflicts across jobs actually bind, or a client who requires a particular file format for submission. That last one decides the purchase more often than any feature, so ask before comparing anything.

What people actually build

Not schedulers. What construction businesses build, when they build, is the layer around the schedule that the scheduling tools deliberately do not cover: capturing progress from site so the programme reflects reality.

That is a mobile-shaped problem. Somebody on site marks activities as started or complete, adds a photograph and a note about why a trade could not get access, and that has to reach the planner without a phone call. Connectivity on a site is unreliable, so anything built here needs to work offline and reconcile later, which is the same constraint that shapes field software generally.

What you would start from here

There is no scheduler in this stack. No activities, no dependencies, no critical path, no float, no baselines, no resource levelling, and no lookahead views. Given that CPM is the category, that is nearly all of it, and the correct recommendation for the schedule itself is to buy a tool.

Where the Vault template helps is the progress capture layer described above: organizations so each project and subcontractor is scoped, roles and invitations so a subcontractor sees their own activities, a Hono backend with Prisma and Kysely on Postgres, an admin app, and Stripe billing if you are selling the tool to other builders. The calendar pack gives events with five views and drag to reschedule, though it has no recurrence rule and no resource model, so it is closer to a site diary than a programme.

You would write the activity and progress records, the sync with whatever scheduling tool holds the programme, and the offline capture path. Treat that last one as the main engineering item rather than an afterthought.

Below is the tenancy, admin, and billing layer that sits under the progress side. For the programme itself, buy a scheduler that does the forward and backward passes properly.