Date: 201702
Local time of day: 0001-0600
Location: ZAU.ARTCC, IL
Aircraft: B737 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class A ZAU
ATC / advisory: Center ZAU
Second aircraft: A321
Reporter organization: Government
Reporter function: Enroute
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Workload; Situational Awareness
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Separated Traffic; Air Traffic Control Issued New Clearance
Contributing factors: Airspace Structure; Chart Or Publication; Procedure; Human Factors
Primary problem: Human Factors

Narrative: Sector 52 started out working both aircraft before they were handed off to me at Sector 51/50. The controller at sector 52; for no apparent reason; shortcut Aircraft Y to the TRTLL way point; and shortcut Aircraft X to the ENDEE way point. Both of these fixes are in 51/50's airspace; my airspace. There was no operational reason for short-cutting the aircraft; and there was no issue with sequencing; so it wasn't for spacing. As a result of the shortcut; the aircraft were put on converging courses; coming together in my airspace. Both aircraft WERE on RNAV STAR arrivals with altitude restrictions built into the arrivals. By short-cutting the aircraft; all crossing restrictions along the arrivals were removed. As a result; I had to give a multitude of clearances to the pilots to ensure separation of the aircraft during their descent. The controller working sector 52 at the time has been repeatedly talked to about actions that result in this scenario. Our RNAV STARS were designed in collaboration with the airlines; pilots; and controllers. They were designed to not only be more efficient for the airlines by saving time and fuel; but also to build a safety net into the system by building in altitude separation between the arrivals; and also by lessening pilot and controller workload. Had both aircraft stayed on their RNAV arrivals with no shortcut; I simply would have said 'Aircraft Y; descend via the TRTLL4 arrival; ORD altimeter XXXX. Aircraft X; descend via the ENDEE4 arrival; MDW altimeter XXXX.' These two clearances are simple; programmed in the FMS on both aircraft; lower the chances of read back errors; and automatically separate the aircraft during their descent. As a result of the short cuts; and the aircraft now being put into conflict; aside from unnecessarily turning aircraft; my only other option was to give multiple clearance to ensure separation. This put unfair workload on the pilots; myself; and was completely inefficient and unfair for Air Carrier Y; as it was a much less efficient descent profile. In this scenario Aircraft X was given a crossing at ENDEE; and Aircraft Y when I was able to was issued the altitudes reference the conflict with Aircraft X; was first issued 20000 feet; then 17000 feet; then 14000 feet; then issued a crossing at TRTLL at 11000 feet and 300 Knots. Four clearances as opposed to one clearance that would have led to an incredibly efficient descent; which the airlines and pilots prefer.  At this point I'm at a loss. If management isn't going to do their jobs and start enforcing our airspace procedures with this individual I'm not sure what else I can recommend. It's very tiresome to watch the same individual abide by his own rules that quite frankly affect everyone around him in a negative way. Can we please use the system as it was designed?




Synopsis: A Center Controller received aircraft from a sector that were issued direct to fixes off their assigned RNAV routes.