I am a firm believer of using the Paraeto Principle to accomplish goals. However, you also want to size the prize. If there is a problem that creates the most downtime, but another creates a significant more cost – follow the cost as your priority. The idea of chasing a Paraeto is to get the biggest hitters which, in theory, cost the most. Regardless, business decisions are based on cost, and any improvement towards that is the real target. The other idea that moved in priority should be placed in a parking lot (idea chest) and come back to when it is adequate in priority. As you start to dig into the idea chest, use the same criteria to organize the list.
Lastly, be sure to use a time and cost measurement. If an idea saves more in the long run but short term another idea which is a quicker fix with good returns increasing the cash flow, you may wish to consider that idea. It also can be challenged based on your business model,