You can't please all the people all the time... Is 87% OK?

Scheduling is a puzzle, so.... when about twenty five years ago a Computer Science and Engineering major asked me to direct his final project I jumped at the opportunity--as long as the project was a scheduling program. He agreed and...

The defined task was: the best schedule is one where classes taught and classes taken are clumped together as close as possible; and there's only one prep. (See chart 1)

Chart 1

Period
1
2	Take A
3	Take B
4	Teach A
5	Teach A
6
7		Teach A
8		Teach A
9		Take A
10		Take B

The first thing I learned was that scheduling was considered a “classic problem” in computer science--a nice way to say that there are no perfect schedules. 

The system worked  well but, because of the computer memory size, and the many variables in the schedule, pencil and paper had to be used to fine tune it.      

With classes on MWF scheduling it is easier to schedule by hand now--hybrid courses have a non-pedagogical advantage as well!  

Here are some of the issues confronted by a scheduler in the LDSP. 

1.  Courses don't have sections every period; and the distribution of sections in periods is uneven.  Thus, if three  instructors select periods 6 and 7 as their 1/2 choice, at least one will be disappointed.  

Chart 2

Period	1130	1131	1134
1	1
2	1		2
3	1	1	3
4		1	3
5		1	3
6	1	1	2
7	1	1	2
8			2
9	1		2
10			1

2. Only one instructor may be available to teach a specific period. This Fall there were two sections of 1134 taught period 9, and only two instructors available to teach them.  

3.  Many graduate courses are taught in blocks of two or three periods one day, thus whenever a class is scheduled on one day (M-W-F) instructors are unable to teach two or three sections.   

  

4.  We try to accommodate some non university related activities: childcare issues for example: I was a single father of a 4^th and 5^th grader, so I know the trials, tribulations, and the love.  In an instance this semester there were only two instructors available to teach period eight, one with a child that had to be picked up by 15:00. The other instructor's choices were periods 3/4, but he was not blessed with a child to pick-up--guess who is teaching period 8? There is a 

silver lining--next semester this person will be first in line for a perfect schedule, what we call in baseball the make-up call. 

How do I prepare schedules?

I prepare a chart with your preferences from the Schedule Preference Form. The number indicates your preference, the X the time you cannot teach.  (chart 4)

Chart 4

Name	1	2	3	4	5	6	7	8	9	10
Pedro	1	2	X	X	X	3	7	6	5	4

The "make up calls" (see above) are the first names given sections. The next spaces are filled randomly, using your schedule preference emails to randomize the selections: the oldest received are chosen first, or the more recent ones; sometimes from the middle down, others from the middle up.... The scheduled is filled according to preferences, as close as possible to the definition--the best schedule is one where classes taught and classes taken are clumped together as close as possible; and there's only one prep. 

Once done I make an offering of graph paper soaked in rum to the scheduling deities... hoping for the best!

Sometimes there is dissatisfaction. Some folks don't like to have a 2-4 period schedule, instead of 2-3; others want the scheduler to consider a lunch hour; some don't want to teach and take consecutively; others want space between Spanish and Portuguese classes to avoid confusion--having taught Italian and Spanish for a couple of years I understand... 

Ideas to improve the system? Want to help with the Spring schedule? Let me know!

And then, there is this,  received at 15:00 the day before classes start...

 When I sent you my schedule I was still waiting for a professor's response about a course. I just got the answer and the class is at the same time than one of the class periods I have to teach (period 6). I was wondering if at this point in time there is anything I could do to maybe change the class period with one of my colleagues. My guess is that it is impossible, but I thought I should try since I really wanted to take that course. I am so sorry about the inconvenience and I completely understand if there is nothing that can be done.