When to strictly avoid multitasking

The problem: Mistakes and errors caused by multitasking
Multitasking often results in mistakes and errors as you forget about a task while occupied with another or because because you get in time trouble and hurry because you loose too much time switching tasks (overhead).

The reason: While multitasking your attention to the single task is reduced.
Often longer lasting tasks involve long waiting times. Although many life hackers warn about multitasking and recommend to avoid it, there are some tasks that continuously ask for multitasking because they are simply very time consuming while not needing the full attention or come along with long waiting times between several actions.

The solution: Only multitask jobs that come to a proper end themselves.
When analyzing my multitasking behavior and the cases where problems occur due to multitasking habit I found out that safe multitasking can only be done for tasks that can be checked at whatever time if they came to a proper end. An important thing is that when multitasking the multiple jobs should not run on same priority. There should be only one active task that has your full attention. Other tasks - those that safely can come to a proper end left on their own - should run as "background task".

Samples for tasks that can be safely run in background:

• Washing clothes (Washing maschine)
• Copying files on your computer, burning CDs/DVDs, ...
• Filling your tank at the gas station (usually can be fixed and it quits automatically when the tank is full)
  

Samples of tasks that should NOT be run in background:

• Cooking
  Why not: If you watch the milk to boil it will boil in the moment you look out of the windows.
  
  
• Filling a big bucket of water (inside house)
  Why not: When you forget about the tasks the water runs out on the floor
  
  
• Handling less important phone calls.
  Why not: Even if your mom talks long about something very unimportant the subject might change and suddenly something important is said.

The point is that you should only run tasks in background that you can safely forget about.

Related posts: Why not multitasking how to, Reduce the stress factors.