Multitasking is the culprit.  Incredibly higher efficiency is the direct result of killing the multitasking, so take aim and fire the first shot.  It's cheap ammunition, aimed at a very high-value target.  Here's the round. 

Send the following message to everyone on your payroll, not in an e-mail but in a real letter:

Multitasking is the practice of performing two or more activities simultaneously, usually for different projects.  This overwhelmingly counterproductive work-model is caused by unresolved conflicts for resources.  So that we might achieve and sustain a significantly greater level of performance, we are taking steps to eliminate all instances of multitasking. 

Until better information is made available to you, please resolve all conflicts for resources, either, by using the prioritized list of projects (see the attachment) or by using information that you know to be more reliable than the attached list.  However you choose to do it, please resolve every resource-conflict, rather than requiring anyone to work simultaneously on two or more tasks. 

From step 4, you have a performance-measurement for the current operation.  If you continue tracking performance for a few months, you'll know just how valuable this one letter will have been to your shareholders.  The cost of the letter, of course, will have been zero dollars. 

--- END ---