Right now the only identifying information for an industry job is the SolarSystemID and the LocationID (output and installed item LocationID that is). This is great for identifying which station in what system you are currently running the job at. However, this is not enough data to do any sort of scheduling, especially when it comes to outposts and POSs.

Lets say we have jobs A, B, and C. Jobs A and B start at the same time in a station, Job C starts a day after both of the jobs end. All we know from this data right now is that A and B cannot be on the same assembly line because their times conflict. We cannot know anything however about job C, which could be on the same line as job A, the same line as job B, or one of a dozen other lines at this station.

Reasons this matters: No interpretation of this data can ever be trusted to be correct. If we try and do scheduling, whether it is for future production or just to see past production, we can never know how many assembly lines were actually used, or how many are available. The most we will know are the maximum amount of time conflicts. This was shown above with Job C having the option of being in Job A's line, Job B's line, or any other line in the station. 

Second problem: Time conflicts with jobs belonging to another player. Once again we have jobs A, B, and C. These jobs are being installed in a very busy station. Jobs A and B were installed at about the same time, however job B needs to wait for another's players job to finish before it can begin. That other players job ends as job A ends. All we see with the API is that Jobs A and B were installed at the same time, but Job B begins about when Job A ends. How do we know they were installed on different lines, or on the same line just back to back? This problem will arise even if the two jobs are not installed at the same time, but rather one started after the other. Same production line? Different production line? Job C is still evil.

Because we do not know the status of all the available lines, we cannot accurately show production schedules, time conflicts, or slot location. In addition, something faced by players in 0.0 is that different lines in the same station will have different fees. I do not know if this happens in empire, but if one line has an hourly fee of 100,000 isk, and another line has an hourly fee of 15,000 isk, we need to be able to interpret the API data to accurately reflect which jobs were installed on which lines.