People will tell you they can multitask but they actually can't.
Those who describe themselves as great multitaskers are probably worst at it.
Avoid forcing people to multitask.
It is difficult for them to do two things at once, for example, have a conversation with a customer while filling out a form on a computer or tablet device. If people must multitask, pay particular attention to the usability of the form.
If you require people to multitask, expect them to make lots of errors and build in ways for them to fix errors afterwards.
Driving while having a cellphone conversation is like driving under the influence of alcohol.