Table 9.1 Questions about demand patterns and their underlying causes. 1 . Do demand levels follow a predictable cycle? If so, is the duration of the demand cycle Ke . One day (varies by hour)? . One week (varies by day)? de One month (varies by day or by week)? by . One year (varies by month or by season or reflects annual public holidays)? ty . Another period? a 2. What are the underlying causes of these cyclical variations? Employment schedules Billing and tax payment/refund cycles Wage and salary payment dates School hours and vacation Seasonal changes in climate . Occurrence of public or religious holidays . Natural cycles, such as coastal tides 3. Do demand levels seem to change randomly? If so, could the underlying causes be . Day-to-day changes in the weather? . Health events whose occurrence cannot be pinpointed exactly? . Accidents, fires, and certain criminal activities? . Natural disasters (e.g., earthquakes, storms, mudslides, and volcanic eruptions)? 4. Can demand for a particular service over time be disaggregated by market segment to reflect such components as follows? . Use patterns by a particular type of customer or for a particular purpose . Variations in the net profitability of each completed transaction