Levels of Optimization

A schedule can be too optimized. A schedule with high utilization (little available time) is usually preferable. However, past a certain point, further optimization can bring diminished cost savings. Furthermore, highly optimized schedules are easily corrupted. Minor changes can cause problems that affect the whole schedule.

For example, consider a schedule for an engineer who is scheduled from 9:00 A.M. to 5:00 P.M. with no available time. If a single appointment runs over, then the engineer cannot complete all activities, leaving at least 1 activity to overtime or the next day. Plus, unexpected events such as a vehicle breakdown can completely disrupt this full schedule.

The goal is to create a schedule that is optimized but still flexible enough to accommodate change. To accomplish this goal, you can use one of the following methods:

• Create constraints limiting the percentage of scheduled hours.

• Extend the duration of activities to leave extra time.

The first method is preferable because it allows managers to set up a dependable level of work. With the second method, managers are not sure of the actual workload for their region.

The balance of working time and available time depends on the business needs. Businesses that require more flexibility (and therefore lower utilization) have the following business requirements:

• High repair volume

• Critical responses (for example, a downed power line)

• Highly variable times for service delivery

• Many short activities (especially in a high-traffic areas)

• Tight contractual requirements

Service businesses that need higher utilization usually have the following business requirements:

• Longer activities (and therefore less travel)

• Preventive maintenance as the main type of service

• Low repair volume

• Longer contractual response times

When determining the best level of utilization, consider your service needs and set an approximate level. Then, adjust the optimization parameters to give the best results.