Prioritize constraints when designing a Transportation Management Center work schedule to help alleviate the complexity of scheduling problems.

The United States and Canada's experience with Transportation Management Center staffing and scheduling.

January 2006
United States; Canada

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Lesson Learned

The design of a schedule depends on a number of factors. Policies establish the work rules that are applied in the context of employee availability and preferences, work demands, and financial constraints, all of which create scheduling constraints. Conflicting constraints often cause problems that must be resolved by the schedule administrator to generate the most desirable schedule.
  • Recognize that equipment availability and the size of a TMC are constraints because they limit the number of employees who can work a shift. The number of operators who can work one shift is limited to the number of workstations available. The number of workstations available may be limited by space or by financial costs. The consideration of equipment must also include contingencies if a piece of equipment should fail or need to be repaired or replaced.
  • Prioritize constraints when designing a work schedule. Generating a schedule increases in complexity as the number of constraints increase. One method to help alleviate the complexity of scheduling problems is to prioritize the constraints. A common method used to prioritize constraints using software is to classify each constraint as a hard constraint or a soft constraint. Hard constraints (e.g., laws, contractual obligations) must be satisfied. Soft constraints (e.g., employee preferences) may be violated to resolve scheduling conflicts. A number of common scheduling policies (or constraints) that should be considered before designing a schedule are listed below.
    • The start times and duration of the shifts
    • The number of hours and days worked per week
    • The maximum/minimum number of consecutive work days (e.g., maximum of 7 days, minimum of 2 days)
    • The maximum/minimum number of consecutive off days (e.g., maximum of 6 days, minimum of 2 days)
    • The minimum number of weekends (e.g., 2 weekends per month)
    • Off days over the weekend should be equally spaced throughout the schedule
    • Shift rotation policies (e.g., rotation can only occur after at least two off days)
    • Permissible shift sequences (e.g., three consecutive day shifts allowed, but an afternoon shift may not follow a night shift)
    • Shift changeover procedures
    • Alternative, reserve, and contingency scheduling and staffing policies
    • The method of shift assignment
    • The staffing levels of the shifts
    • The start times and duration of breaks
    • Overtime and shift differential policies
    • Days-off policies for vacation, sick leave, personal time, jury duty, maternity/paternity leave, etc.
    • Groups or teams of employees that should remain intact throughout the schedule
Although many of the constraints listed above may seem reasonable, including too many of them as hard constraints may create too many scheduling conflicts. Often, constraints may need to be amended to accommodate other constraints. For example, employee preferences may run counter to organizational policies. Violating some of the constraints may enable more desirable schedules. In addition, the importance of the soft constraints may be ranked to help determine which soft constraints may be violated before others. Employee preferences are an important consideration, and several methods may be used to accommodate them. Employee preferences may be implemented into the schedule during the design phase, or employees could bid for shifts in order of seniority or in a lottery system.

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Transportation Management Center Staffing and Scheduling for Day-to-Day Operations

Author: Wolf, Mark B., et al.

Published By: U.S. DOT Federal Highway Administration

Prepared by the Human Systems Engineering Branch Georgia Tech Research Institute for the U.S DOT FHWA

Source Date: January 2006

URL: http://tmcpfs.ops.fhwa.dot.gov/cfprojects/uploaded_files/Final_Technical_Document1.pdf

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Lesson Analyst:

Jane Lappin
Volpe National Transportation Systems Center


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Lesson ID: 2006-00305