The document discusses an online bus ticket booking system created for Udankhatola, a bus transportation company in India. Currently, customers must visit ticket counters to purchase tickets or check schedules, leading to long wait times. The proposed solution is an online booking system allowing customers to purchase tickets 24/7 from any location and check availability before purchasing. It also allows customers to pay during travel rather than with cash at time of purchase. Data flow diagrams at the 0 level and for registered and guest users are provided to illustrate how customer data and reservations will flow through the system.