English Teacher

Really? English?

Invasive goes inside. Non-invasive stays outside, of whatever it is.

Sounds about right. I'm due for my 5 year colonoscopy, and have put off making the appointment for a month. That's invasive maintenance!

If it takes 5 years I think that's well beyond invasive.

No, 5 years is the time you spend on the toilet the day before the exam.

As an example you might go around opening and closing water valves to clear scale build-up and check operation as a non-invasive monthly maintenance procedure, if , for instance you should find that some valve is stuck or not shutting off completely, then an invasive procedure of rebuilding or replacing the valve may be required...

Say, that's a pretty nice valve setup... I know where one hose goes (the one going up), but where does the other one go? Also, what's the purpose of that brass piece between the valve and the hose

I've never seen a set up like this.

Ha! It might well be one of a kind....It's a double female nipple to replace the compression fitting that failed....This is a handy setup for washing out poopy diapers(for those who still use cloth diapers), with the extra line you see going to a kitchen type hand sprayer....If you have babies and use cloth diapers you will instantly get this....

You might install an extra valve here....

http://www.instructables.com/id/Add-a-Shower-to-your-Toilet/

Very clever set up!

Invasive maintenance would involve stopping and or stripping down equipment.

Non invasive could be logging performance and or operating results etc.Or just polishing the brass on a boiler

I am sure you do know the Oxford English dictionary meaning for "invasive" and "non-invasive".

As pointed out, somewhat "tongue in butt" invasive does mean, as you quite rightly put it, "would involve stopping and or stripping down equipment."

It can do, however there are varying degrees of this type of maintenance. That would take way to long to explain.

Non-invasive would be superficial, that it checking that the machine, let's take a small electric motor, does not have loose bolts, the coupling to whatever it drives is good, there is grease in the bearings, and the cable connections are tight.

When working in the steel works, many years ago, we had DC motor to maintain, and one of the jobs was "brush plucking". We would check the carbon brushes by pulling on the wire connection to see if the spring was tensioned, the brush would last until the next PM day and it was in one piece. Total time of 5 seconds, but you'd have HUNDREDS to do! That would be considered non-invasive!

Oh, and take no notice of this lot... they can be quite amusing at times, but they have a good heart, and one or two have a good bowel movement too!

Invasive maintenance in my understanding would mean that you have to stop the process, Noninvasive maintenance would mean that the process or machinery could continue to function while doing maintenance.

The difference between open heart surgery and eating the right foods and getting enough exercise.

Non-invasive maintenance would be the checks referred to earlier along with adding grease and or oil to moving parts. Stopping a machine to change the oil or grease would be invasive.

As per wordweb:

Invasive

adj.

1. Of, engaging in, or given to armed aggression: an invasive military force.
2. Marked by the tendency to spread, especially into healthy tissue: an invasive carcinoma.
3. Of or relating to a medical procedure in which a part of the body is entered, as by puncture or incision.
4. Tending to intrude or encroach, as upon privacy.

Read more: http://www.answers.com/topic/invasive#ixzz2MOqcOfd3

Invasion of privacy

Attacking

Noninvasive

Wordweb

(medicine) relating to a technique that does not involve puncturing the skin or entering a body cavity

1. (medicine) Of a surgical or other medical procedure, not requiring an incision.

1. not penetrating the skin, e.g. a non-invasive test.
2. a neoplasm which spreads over a surface and does not invade and destroy healthy tissue.

Read more: http://www.answers.com/topic/non-invasive#ixzz2MOt1i7n6

non invasive means you don't invade it. Its a 'look see' with your hands in your pockets. Its an oil change, its a filter change at most.

Invasive means you are stripping things down, opening them up and poking around in such a way repairs will be needed. It might be you need to scrape paint of things, do tests for corrosion all, grind the top off a transformer etc. You will need then to do repair works.