2.009 Product Engineering Processes


This exercise, to make an origami ball, was used to determine a representative time multiplier for a simple, well defined, familiar and unfamiliar fabrication task.

Students unfamiliar with origami estimated, on average, that it would take only slightly longer than to make the ball as did students with origami experience. Typically, they took about 2-3 times longer. However, in isolation they would have likely taken significantly longer than they had predicted ...when students familiar with the ball had completed their own ball, they helped the inexperienced students and thereby significantly lowered their time to complete the ball.

For those unfamiliar with making the ball, the actual time to make the ball was 0.5X to over 10X higher than the time they estimated, centered around 2X (with high variability). For those familiar with the origami ball, the actual time was slightly over 1X higher than their estimated time (with much less variability).

When estimating the time needed to complete a task, it is important to consider the task's familiarity, complexity, and process uncertainty. When developing a schedule, always add an appropriate multiplier when allocating the time needed to complete a task.

Ball fabrication instructions
Plots of estimated fabrication time
Plots of actual fabrication time
Plots of actual fabrication time/estimated fabrication time