Construction schedule

Edit the activities (JSON: id, days, after, optional crew, lag, name, exposed, and notBefore: a "YYYY-MM-DD" date before which an activity cannot start, such as a lumber delivery or a permit) and get the critical path, slack, dates with the crews you typed, and what a slip does to the finish. The durations are yours; none are shipped. Nothing leaves your browser.

Schedule Weather allowance on exposed activities (% of working days lost, your figure, 0 to 100; blank for none). Mark an activity "exposed": true in the JSON. Monthly weather rates (optional; % of working days lost by the month an activity starts, your figures, like 2026-03=20, 2026-04=12). Listed months replace the flat figure above. Hold dates (optional; the earliest an activity may start, by id, like plumb=2026-04-03, roof=2026-04-20: a delivery or a permit, your dates). They replace any notBefore in the JSON for the ids listed. Activity costs (optional; dollars by id, like frame=18000, roof=9500: your quotes, none shipped). They replace any cost in the JSON for the ids listed, and the report adds spend by month. Carrying cost per extra working day (optional; dollars: loan interest, insurance, site costs, your figure, none shipped). Each slip then shows what it costs, and the total carry for the job is shown. Contract completion date (optional; YYYY-MM-DD, your date). The report then says how many working days late, or to spare, the finish with your crews is, and the carrying cost of the late days if you typed one above. Day ranges for risk (optional; id=min-max working days around the activity's days, your guesses, like walls=6-14, roof=4-9). Adds a Monte Carlo finish: P50, P80 and P90 dates, the chance of the contract date and which activities are most often critical.

Do the whole house: framing, sheathing, budget and schedule in one takeoff

How it is counted

Critical path. A forward pass gives each activity's earliest start, a backward pass its latest; zero slack means critical.
Crews. With a crew count per name, a greedy pass delays activities that would need more crews than you have. It is a heuristic, not an optimal resource schedule.
Calendar. Working days are Monday to Friday, less any holidays and weather days you list.

Questions

What is the critical path in a construction schedule?

The critical path is the chain of activities with zero slack: if any one of them runs late, the finish date moves by the same number of days. This tool finds it with a forward and a backward pass over the predecessors you type.

Does this tool know how long framing or drywall takes?

No. It ships no durations. Every duration, predecessor and crew count is yours, from your own crews and past jobs. The sample is only there to show the format.

How are weekends, holidays and cure time handled?

Weekends are skipped. Holidays and weather days are dates you list. Cure time or an inspection wait is a lag in working days after the predecessors finish. Weather is not forecast.