solution

An online university has a stable average student population of 23,000 over the years. The
university offers modular courses and curricula such that all tracks of majors and concentrations
have the following sequential stages with their corresponding designed durations:
Stage 1 – General education courses (6 months)
Stage 2 – Foundation courses (9 months)
Stage 3 – Major courses (18 months)
Stage 4 – Concentration courses (15 months)
The university does not take transfer students. New students can enroll at any time during the
year and start with Stage 1. After enrolling, students can choose their tracks and start taking
online courses. With online courses, there is no wait time between stages. Students can choose
to drop out at the end of some stage. Hence, students have their own start and end dates.
Statistics show that, at any point in time, the average number of students in the first
stage is 3,170; in the second stage 4,510; in the third stage 8,540; and in the fourth stage 6,780.
After the fourth stage, 240 students drop out on average (recorded over 15 months), and the
remaining students graduate. Note that all drop outs are recorded at the end of the stages.

The retention rate at each stage is the proportion of students who finish the stage and
move on to the next one or graduate. The retention rates do not only affect revenues but also
the university’s rankings. The university’s president observes the retention rates very closely
and takes actions if there are signs of declining retention rates.

In the following questions, you should convert all quantities into yearly numbers.

(a)[2] Draw a process flow diagram showing how students move through different stages. Make
sure to have process boundaries in the diagram. Note that there is no wait time.
(b)[1] What is the number of new enrollments every year?
(c)[2] What are the yearly dropouts from individual stages? (4 separate dropout numbers)
(d)[1] What is the retention rate of Stage 1? (%, 2 decimals, for example 79.54%)
(e)[1] What is the retention rate of Stage 2? (%, 2 decimals)
(f)[1] What is the retention rate of Stage 3? (%, 2 decimals)
(g)[1] What is the retention rate of Stage 4? (%, 2 decimals)
(h)[1] What is the proportion of newly enrolled students who would eventually graduate? (%)