Tally, SpEd Scheduling

Tally is an open-source scheduling engine and compliance ledger for special-education service minutes, and it closes a loop every existing tool leaves open. Every student on an IEP is legally owed a set number of service minutes each week (speech, OT, PT, counseling), and a single school-based clinician carries around 50 of these students across two campuses with different bell schedules, no IT department, and no integration budget. Building a conflict-free pull-out schedule by hand eats entire weekends, and proving the minutes were actually delivered is the part that carries the real legal exposure. The market splits into two camps that never meet. Generators build a schedule and never check whether sessions happened, and trackers log delivery but cannot build the schedule. Neither owns the gap between mandated minutes and delivered minutes, and that gap is the whole legal story. After Endrew F. (580 U.S. 386) an IEP has to be reasonably calculated to enable progress, so when a district is challenged the mandated-versus-delivered delta is the defense file. That exposure is compounding: state special-education complaints rose 22% in a single year and now run roughly 80% above their ten-year average, and a district's central vulnerability in a due-process hearing is the absence of delivery data. Tally owns that gap end to end. A deterministic OR-Tools CP-SAT solver builds a conflict-free, bell-schedule-aware schedule against each school's real periods and protected blocks, using day-types (A/B/rotating) rather than weekdays. A three-column ledger tracks mandated, scheduled, and delivered minutes per mandate, with the delta always visible and never rounded away. A missed session re-enters the solver as demand and lands in open capacity or surfaces as an explicit shortfall, so nothing is ever dropped silently. And every mandate exports against the configured state rule, with Illinois shipping as the demo (a 10-school-day makeup clock and a 3-school-day parent notice), kept as config rather than hardcoded constants. What makes it trustworthy in a regulated space is the solver itself. Scheduling is deterministic, so the same input returns an identical, fully explainable placement and no model decides where a student goes. A coordinator can defend every slot, and a district gets an audit trail instead of a black box.