Science & Industry

PE when referring to a blueprint is the "Productivity Level" as described on the print's attributes tab. Higher values will see jobs initiated from this print completing in less time.

It's easily confused with the character skill Production Efficiency (levels of which reduce wastage, ie. reduce the materials needed).


EDIT:
Further clarification.

Speed of completion of a manufacturing job is affected by two things - the character's Industry skill and the print's Productivity Level (generally referred to as a print's PE level).
Materials used for a manufacturing job are affected by two things - the character's Production Efficiency skill (which is sometimes shortened as PE skill, hence the confusion), and the print's Material Level (generally referrred to as a print's ME level).

PE isn't generally as important as ME depending on the blueprint.

Depending on the blueprint, ME4 either adds a good value (in the case of capital ships etc where it can take more than a month to do 1 level of ME) or not much value at all (like ammunition, since it doesn't take much time to get it to ME4 and is quite pointless since once it's actually in a research slot, you might as well do more ME)

PE only affects the time taken to build off the blueprint, so unless you're planning to build lots of the items, it doesn't make that much difference (I'm likely to get shot down in flames with stuff like "Isk per Hour" etc, and "Slot Costs") but meh

Thought I'd add a couple points to this thread on top of what's already been stated.

Rule #1, you have to decide what levels of ME and PE you want for your own purposes. For example, I do a lot of Invention, so the ME & PE have zero meaning for me for prints that I will use to make copies of for Invention purposes. For my own use, ME is great, but I'm not going to go nuts on getting it up high. When building for myself, moderate ME and zero PE is fine. I have no need for speed when I'm manufacturing stuff (added costs if manufacturing in-station are irrelevent to me: I don't build caps), so I don't care one whit about it. If you're building something in-station that has a long build time, PE obviously matters here.

Rule #2: Ignore the "perfect" non-sense. People try to buy and sell prints that are "perfect" and ask a premium for that. Do the research (as in markets and costs research) yourself, and decide what's adequate for you. I get PE up to an acceptable level FOR MYSELF when I'm making copies to sell; I never try to get to "perfect" on any prints, because it's pretty much a waste. Only a noob with zero experience will buy a print just because the ME/PE levels are insanely high.

Rule #3: consult Zofu's site (http://zofu.no-ip.de/bpo) to determine what levels of ME & PE are good for your purposes. If you're buying a print, always check this site to see if you think the price being asked is adequate for you. Again, this comes down to market research, as always.

One thing not mentioned above is that the PE level impacts the rental cost of a manufacturing facility if you are building at an NPC facility.

Higher PE means less time to produce, thus lower rental costs, outside of shorter production runs.

What is hard to get without a tool to do the math for you for a given BPO is at what point the PE and ME values have no practical meaning, and as is said above, the practical meaning has to do with what YOU want to do, not what the perfect values are. To do this, you really want to use a tool that does all these computations and takes into account your particular context.

There are so many variables here you can go bananas.

Z