Overview
During PBS processing, the system may assign coverage awards (pairing unstacking) to ensure that all required pairings are allocated.
Certain bid types, specifically “Add Rule” conditions, are not considered during this phase. This article explains how these rules behave, with a focus on: Set Condition No Same Day Pairings
Add Rule Bids
Add Rule bids define conditions that must be satisfied across the entire pairing line.
Examples include:
Set Condition No Same Day Pairings
Set Condition Min Days Off
Set Condition Max Days On
Set Condition Consecutive Days Off In A Row
Set Condition Minimum Base Layover
Set Condition Pattern
Set Condition Days Off With Employee
Set Condition Days Off Opposite Employee
These rules are evaluated at the line level, not incrementally.
Behavior During Coverage Awarding
During coverage awarding:
The system may force pairings into a line to meet coverage requirements
Add Rule bids are not considered when selecting these pairings
If a coverage award results in a violation:
The rule cannot be partially enforced
The system does not attempt to re-apply it later
The rule is considered not satisfied for the entire line
As a result, the associated bid group may be denied.
Example: No Same Day Pairings
A bidder includes:
Set Condition No Same Day Pairings
If coverage awards introduce pairings on the same day:
The condition becomes violated
The system cannot resolve the violation within the line
The rule is no longer enforced
The bid group may fail
Comparison with Other Bid Types
Prefer Off / Avoid
Considered during coverage awarding
The system attempts to minimize violations
Add Rule Conditions
Not considered during coverage selection
Must be fully satisfied
If violated → not applied
Else Start Next Bid Group (ESNBG)
When an Add Rule is combined with: “Else Start Next Bid Group”
Behavior:
Coverage awards are still assigned without considering the rule
If the final line violates the rule:
→ The system triggers Else Start Next Bid Group
→ Processing continues with the next bid group
Note:
ESNBG does not prevent violations during coverage. It only defines the behavior after evaluation.
Why This Behavior Occurs
PBS builds lines:
Sequentially, in seniority order
Using remaining available pairings
When unallocated pairings accumulate (stacking), the system must:
Assign these pairings through coverage awarding
Prioritize feasibility of line construction
Because Add Rule conditions apply to the entire line, they cannot be enforced if coverage assignments create conflicts.