The Toronto Area Scheduling Model for Household Agents (TASHA), a new prototype activity scheduling microsimulation model, generates activity schedules and travel patterns for a 24-h typical weekday for all persons in a household. The prototype model is based solely on conventional trip diary data and therefore is applicable in many urban areas where activity data may not be available. The model makes use of the concept of the project, a "container" of activities with a common goal, to organize activity episodes into the schedules of persons in a household. A heuristic, or rule-based, method is used to organize activities into projects and then to form schedules for interacting household members. The TASHA model is considered to be a successful first attempt to operationalize a generalized conceptual model of household decision making, with reasonable correspondence between model and observed trip rates and chain characteristics.