Electrical Line Magazine has featured the whitepaper “LED Tube-Based Troffers vs. Integrated Fixtures” in their magazine.
For nearly all lighting applications of the past century, light fixtures and light sources were manufactured as separate products. The short service life of incandescent bulbs and fluorescent tubes meant that ease of replacement was crucial, and these products fit that requirement. As LEDs became commercially viable, they transformed lighting with both increased energy efficiency and long service life. Lighting became less like other household or maintenance facility supplies, no longer requiring a small stockpile of replacements waiting to replace a failed bulb or tube, and more like a furnace or roofing, which could be installed and let be for many years.