Some enviroments require potting. Water, oil, dust or sand. Sometimes heat. You can make your product a lot more durable.
For diy, you use two-component epoxy. Doesn't fully harden, it stays rubberish. It also only lasts 5 to 7 years before drying out and cracking. If used in environments where it is a bit hot.
If you outsource it, they use polyurethane. Turns into a solid black block. Still a bit flexible, lasts ages.
You can pot top-down into a enclosure, but also using molds.
http://www.purtec.nl/im_el16.jpgYou decrease the repairability figure to 0, removing it requires heat and scratching tools. Only usefull if there is enough time available and money to gain.