Is there a word for doing work like this? For example when you have a lot of outages, you would say your power supplier is working ...ly. Something like inconsistent or erratic but with a less forgiving connotation.
A word often used in this connection is sporadic.
sporadic (adj.): occurring occasionally, singly, or in irregular or random instances
Your power supplier is working ineffectively.
1: not producing an intended effect
2: not capable of performing efficiently or as expected