Advanced Engineering Skill Application

[Kytross]

You can modify existing gear wirh repair skills to a maximum +1D+2 with no penalty.

You can jury rig existing gear past +1D+2 with significant penalties.

To redesign gear past 1D+2 without penalties, or design new gear, you need (A) Engineering

[Tinman]

The (A) Droid Engineering skill is covered extensively in (WEG 40116) Cynabar's Fantastic Technology: Droids. The system contained in that book mostly covers designing and building new sorts of droids (either from prefabricated parts or from scratch, though the latter is quite time consuming and very difficult.)

The few times (A) Engineering skills have been used in any of the games I've run or participated in, they've usually allowed characters to do things technicians ordinarily wouldn't know how to do, on top of being used to design new items.

As an example, in our Rebel Alliance privateering game, we had an actual engineer (space transports) as our engineering officer. There was a particular instance in which the ship's computer had been sabotaged to prevent hyperdrive jumps. He managed to force the nav computer into simulation mode, feed it data from position sensors as if they were test parameters, then (with the safeties off) shunt the calculations to the hyperdrive motivator through the buffer of an astromech as a workaround in order to avoid imminent capture. (It was an extremely rough jump, severely damaged the main hyperdrive, and fried the astromech.. but it worked.)

In a couple other instances, he was able to make parts not designed for our vessel temporarily work with the ship in order to get us to where we could make more conventional repairs (with proper materials.)

[dic1]

The only times it was used in a game i played in the gm let a player with space transports engineering make a roll (can't remember the tn), success let them reduce the time it took to replace a blown hyperdrive.
Basically they understood how the ship worked as more of a whole system rather than individual components.