It is not always possible to explicitly assign the concepts of “Out-tasking” and “Business Process Outsourcing” - as defined in the information security policy for outsourcing – to the types defined in the table below. However, type 1 corresponds more strongly to the concept of “Out-tasking”, whereas type 2 is more likely to be assigned to the concept of “Business Process Outsourcing”.

В таблице эти типы обозвали так:
Type 1: “on site” or remote access
Type 2:
commissioned data processing

Out-task

Often used along with outsource, out-tasking is different from outsourcing in that out-tasking is usually done on a smaller scale and for a shorter period. A one-time project would be considered out-tasking rather than outsourcing.

http://www.internetmarketingdefinitions.com/Outtask

и вот отличное объяснение на квазижизненных примерах

http://www.evancarmichael.com/Business-Coach/2148/Outtasking-or-Outsourcing--Which-Would-You-Choose.html

выводы:
out-tasking больше похоже на подряд
outsourcing так и остаётся аутсорсингом