2.12. How the Schedule is Generated

The schedule is generated based on specific criterion.  If the application is generating a new schedule, the first issue addressed is that of critical conflicts.  The application doesn't create a schedule which has a critical conflict, and if no schedule exists without conflicts then certain default values are assigned.  If an instructor is not found for a course, the course is scheduled with the instructor set as STAFF, or if a room is not available for a course, the location is set to TBA (to be announced). 

Critical conflicts which are resolved with a STAFF assignment:

• One instructor teaching two courses at the same time
• An instructor assigned to a course he or she is incapable of teaching

Critical conflicts which are resolved with a TBA assignment:

• One room scheduled to house two course sections at the same time
• A course section is assigned to a room which is smaller than the desired size of the course section
• A lab course is assigned to a room which does not have lab capabilities

After critical conflicts criteria are met, the application attempts to create a schedule which best meets the preferences of the instructors.  The preferences are taken from the copy of the instructor database saved within the particular workspace, and so the preferences may have been changed to the schedule administrator's preferences.  A series of preference criteria are evaluated on a point scale for each potential course, instructor, and classroom placement (collectively called a "time block"), and the schedule which is selected is the one with the fewest TBA and STAFF assignments and the highest average point value for all scheduled sections.  The preference criteria are as follows:

• (Criteria A) Does the course fit well with the instructor assigned to it based on the instructor's teaching abilities.
  Ratings are assigned based on this criteria as follows:
  • 5: Course is assigned to an instructor who has rated his or her teaching ability for the course as a 5.
  • 4: Course is assigned to an instructor who has rated his or her teaching ability for the course as a 4.
  • 3: Course is assigned to an instructor who has rated his or her teaching ability for the course as a 3.
  • 2: Course is assigned to an instructor who has rated his or her teaching ability for the course as a 2.
  • 1: Course is assigned to an instructor who has rated his or her teaching ability for the course as a 1.
  • 0: Course is assigned to an instructor who has rated his or her teaching ability for the course as a 0.  This is considered a critical conflict condition, but may occur if the application user forces the course assignment in schedule edit mode.
• (Criteria B) Does the time slot fit well with the instructor's preferred times to work.
  Ratings are assigned based on this criteria as follows:
  • 5: Time block of the scheduled course is completely within the instructor's desired times to work as specified in the edit instructor interface.
  • 4: Time block of the scheduled course is scheduled such that less than one half hour of the course, in one day, is outside the instructor's desired times to work.
  • 3: Time block of the scheduled course is scheduled such that more than one half hour but less than one hour of the course, in one day, is outside the instructor's desired times to work..
  • 2: Time block of the scheduled course is scheduled such that one hour or more, but less than two hours of the course, in one day, are scheduled outside the instructor's desired time to work.
  • 1: Time block of the scheduled course is scheduled such that two hours ore more, but less than two and a half hours of the course, in one day, are scheduled outside the instructor's desired time to work.
  • 0: Time block of the scheduled course is scheduled completely outside of the instructor's desired time to work.
• (Criteria C) Do the days of the scheduled course fit well with the instructor's preferences for that course.
  Ratings are assigned based on this criteria as follows:
  • 5: Course is scheduled in a time arrangement for which a rating of 5 is assigned in the edit instructor interface.
  • 4: Course is scheduled in a time arrangement for which a rating of 4 is assigned.
  • 3: Course is scheduled in a time arrangement for which a rating of 3 is assigned.
  • 2: Course is scheduled in a time arrangement for which a rating of 2 is assigned.
  • 1: Course is scheduled in a time arrangement for which a rating of 1 is assigned.
  • 0: Course is scheduled in a time arrangement for which a rating of 0 is assigned.
• (Criteria D) Is the scheduled classroom close to any classrooms for courses which the selected instructor is scheduled to teach in adjacent timeslots.  This distance is derived by using the Pythagorean theorem based on the location (specified in the edit classroom interface) of the classroom being scheduled and the locations specified for any courses scheduled adjacent to the time block which have the same instructor.  Specifically, if the classroom being scheduled is "this" and the adjacent classroom is "that", and the location coordinates are x and y, then the distance between the two is equal to the square root of ( ((this x) - (that x))² + ((this y) - (that y))² )² ).  The largest distance between two rooms, which is re-evaluated after each classroom add or edit and then stored, is simply the largest value of this computation.
  Ratings are assigned based on this criteria as follows:
  • 5: No courses are scheduled in adjacent time blocks which have the same instructor as the time block being rated, or if such a time block exists and the adjacent time block has a classroom assigned to it, the distance between the two classrooms is 10% or less of the largest distance between two rooms.
  • 4: One or more adjacent time blocks has a classroom assigned and has the same instructor assigned as the time block being rated, and the greatest distance between the classroom for the time block being rated and the classrooms in these adjacent time blocks is between 10% and 30% of the largest distance between two rooms.
  • 3: One or more adjacent time blocks has a classroom assigned and has the same instructor assigned as the time block being rated, and the greatest distance between the classroom for the time block being rated and the classrooms in these adjacent time blocks is between 10% and 30% of the largest distance between two rooms.  This rating is also assigned if an adjacent time block has the same instructor assigned as the time block being rated, but no classroom has been assigned (it is set to TBA) for the adjacent time block.
  • 2: One or more adjacent time blocks has a classroom assigned and has the same instructor assigned as the time block being rated, and the greatest distance between the classroom for the time block being rated and the classrooms in these adjacent time blocks is between 30% and 60% of the largest distance between two rooms.
  • 1: One or more adjacent time blocks has a classroom assigned and has the same instructor assigned as the time block being rated, and the greatest distance between the classroom for the time block being rated and the classrooms in these adjacent time blocks is between 60% and 80% of the largest distance between two rooms.
  • 0: One or more adjacent time blocks has a classroom assigned and has the same instructor assigned as the time block being rated, and the greatest distance between the classroom for the time block being rated and the classrooms in these adjacent time blocks is between 80% and 100% of the largest distance between two rooms.
• (Criteria E) Does the classroom meet the handicap criteria.
  Ratings are assigned based on this criteria as follows:
  • 5: The instructor assigned to the time block being rated is handicapped and the classroom assigned to the time block is handicap accessible, or the instructor is not handicapped.
  • 0: The instructor assigned to the time block being rated is handicapped and the classroom assigned to the time block is not handicap accessible.
• (Criteria F) Does the classroom meet the room resource (such as VCR and smart room) criteria desired by the instructor.
  Ratings are assigned based on this criteria as follows:
  • 5: 90% to 100% of the resources requested by the instructor in the instructor preferences interface for the course specified in the time block being rated are available in the classroom assigned to the time block being rated.
  • 4: 80% to 90% of the resources requested by the instructor for the course specified in the time block being rated are available in the classroom assigned to the time block being rated.
  • 3: 60% to 80% of the resources requested by the instructor for the course specified in the time block being rated are available in the classroom assigned to the time block being rated.
  • 2: 40% to 60% of the resources requested by the instructor for the course specified in the time block being rated are available in the classroom assigned to the time block being rated.
  • 1: 20% to 40% of the resources requested by the instructor for the course specified in the time block being rated are available in the classroom assigned to the time block being rated.
  • 0: 0% to 20% of the resources requested by the instructor for the course specified in the time block being rated are available in the classroom assigned to the time block being rated.
• (Criteria G) Is the classroom the right size for the course section being assigned.
  Ratings are assigned based on this criteria as follows:
  • 5: The size of the course section for the time block being rated is between 90% and 100% of the size of the classroom for the time block.
  • 4: The size of the course section for the time block being rated is between 70% and 90% of the size of the classroom for the time block.
  • 3: The size of the course section for the time block being rated is between 50% and 70% of the size of the classroom for the time block.
  • 2: The size of the course section for the time block being rated is between 30% and 50% of the size of the classroom for the time block.
  • 1: The size of the course section for the time block being rated is between 20% and 30% of the size of the classroom for the time block.
  • 0: The size of the course section for the time block being rated is between 0% and 20% of the size of the classroom for the time block.  This rating is also assigned if the desired size of the course section is greater than the size of the classroom assigned to the time block.  This is a critical conflict condition, however it may occur if the user forces the classroom assignment in schedule edit mode.

Not all criteria is used for each rating determination.  The rating is based on which elements of the time block are present in the time block.  If the rating is being determined while trying to add an element to time block, the rating is determined as if that element is already part of the time block.

• Ratings for time blocks which include a course, instructor, and classroom are determined by taking the sum of ratings from criterion A through G, dividing that sum by the number of possible points (7 criterion times 5 points each) and multiplying this fraction by 100 to get an overall time block rating between 0 and 100.
• Ratings for time blocks which include a course and instructor, but no classroom are determined by taking the sum of ratings from criterion A through C, dividing that sum by the number of possible points (3 criterion times 5 points each) and multiplying this fraction by 66 to get an overall time block rating between 0 and 66.  This rating is still evaluated on a scale of 0 to 100 like all other time blocks, and the maximum value of 66 is considered a penalty since 1/3 of the elements in the time block are unassigned.
• Ratings for time blocks which include a course and classroom, but no instructor are based solely on criteria G and the rating is scaled to a 66 point scale by taking this rating, dividing by 5, and multiplying by 66.  This rating is still evaluated on a scale of 0 to 100 like all other time blocks, and the maximum value of 66 is considered a penalty since 1/3 of the elements of the time block are unassigned.
• Ratings for time blocks which include only a course and no classroom or instructor are assigned a 50 out of 100 since two major pieces of this time block are missing.

Time blocks which are missing an element (course, instructor, or classroom) are penalized two-fold:  they are allowed a lower maximum point value than a fully assigned time block, and they include a STAFF instructor assignment and/or TBA classroom assignment.  The schedule chosen is the one which primarily has the fewest STAFF and TBA assignments and secondarily which has the highest average rating (on a 100 point scale) for all the time blocks in the schedule.

If the user has already generated a schedule and is now trying to update the schedule, the application follows the same guidelines as for a new schedule, except that it schedules around the time blocks which have been locked in the schedule edit mode.  These blocks are locked because they have the "Do not allow auto-generator to edit" property set to true, as discussed in the edit schedule section.  Note that if the user has manually scheduled such that a critical conflict exists, the critical conflict is preserved but the user is shown a warning such as that in Figure 2.12-1.

Figure 2.12-1: Warning displayed if manual edits create a critical conflict.