A sales territory groups customers and prospects and assigns them to an individual salesperson. Territories are established to thoroughly cover the market, establish salesperson responsibility, evaluate performance, improve customer relations, reduce expenses, and match salespeople to customers, benefiting both. Territories are designed by selecting a basic geographical control unit, determining sales potential in each unit, tentatively establishing territories, evaluating customer contact plans, and assigning territories. Territories are then evaluated and revised as needed based on factors such as customer numbers, locations, sizes, call times, frequencies, and travel times.