Date: 201606
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Light: Night
Aircraft: Any Unknown or Unlisted Aircraft Manufacturer
Airspace: Class A ZZZ; Class E ZZZ
ATC / advisory: Center ZZZ
Reporter organization: Government
Reporter function: Supervisor / CIC
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Workload; Distraction; Situational Awareness
Anomaly: ATC Issue All Types; Inflight Event / Encounter Weather / Turbulence
Detector: Person Air Traffic Control
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Company Policy; Human Factors; Staffing
Primary problem: Staffing

Narrative: I am submitting this report to clarify an event completed by a ARTCC Area 4 controller regarding staffing and sector configurations. I was made aware of the event by the facility representative who was concerned about the late night staffing in Area 4.I was the OMIC (Operations Manager In Charge) that evening. When I reported; I was briefed by the dayshift WSIC (Watch Supervisor In Charge) that Area 4 had 8 people (6 CPC and 2 D Sides). If there was a request for OT (Overtime) it would have occurred on the dayshift. The area ran routinely for the first part of the evening with 8 people and a FLM. Area 4 normally schedules 3 people on 4-midnight [weekend] shifts and routinely allows one of those people to take leave without backfill. Overall; the 8 people were not overworked in terms of total TOP (Time On Position) with the shift average at 278 minutes. However; late in the evening after I had gone home; I was told that staffing was insufficient. My investigation revealed a confluence of factors led 2 controllers to work extremely hard for the last 90 minutes of their shift. There was late traffic and weather. Normally ZZZ ARTCC works sub 4000 counts on [weekends] and rarely are any of ARTCC's sectors overload on [weekends]- it's our slowest day of the week and Area 4 routinely runs with 3 sectors open on [weekends]. The Area sup had left at XA:30 to meet fatigue requirements for a return at XJ:30. The OM (me) had also left at XA:30 in order to return at XJ:30 the next morning. The midnight sup was handling Area 4 and the situation did not develop until the two people working [the evening shift] had already departed for the evening. This left only the two 4-midnight controllers working two busy sectors without any additional personnel to coordinate or open additional sectors. Had the weather/traffic been predictable; or had the Area 4 sup not gone home for the evening; one of the [evening] people would have been held over for 1-2 hours of overtime.I have already discussed with the Representative for ZZZ ARTCC; the Area 4 rep; the Area 4 manager; and the Area 4 scheduler to backfill for the remainder of the convective season with a third controller working 4-midnight on [weekends]. This is primarily a result of the fact that we cannot force the midshift personnel to report any earlier than XD:54. Each of the following 2 weeks we held over [evening] staffing on OT until the scheduler could properly schedule additional personnel more than 1 pay period out. Additionally as a countermeasure; I have asked the FLM in Area 4 to evaluate traffic and CIC coverage to make a week by week determination on their own shift. Some weeks it may be better for the FLM to stay until [the late evening] even though it means they cannot report the next day until [morning]. They need to weigh staffing/CIC coverage each [weekend].




Synopsis: ARTCC Operations Manager reported of a shift where staffing and sector configuration was questioned.  Controllers became busy with late traffic and weather after all others left on a mid-shift.