Building Operating Management, May 2014, by Greg Zimmerman.
http://www.facilitiesnet.com/lighting/article/Case-For-Capital-Investment-In-Lighting-Upgrades-Rests-On-Showing-Specific-Benefits--14924

"When justifying a lighting upgrade, here are some arguments to include, and some to think twice about.

A 4-part article:
Part 1: Case For Capital Investment In Lighting Upgrades Rests On Showing Specific Benefits
Part 2: Benchmarking, Rebates And Incentives Can Help Justify Lighting Upgrades
Part 3: Combine Lighting Upgrades With Other Capital Projects To Maximize Energy Savings, Minimize Disruption
Part 4: Overselling Productivity Increases, Maintenance Savings Can Hurt Chances Of Approval For Lighting Upgrades