Scenario Editor

Build the model before optimizing it

The Scenario Editor organizes setup into Model, Requirements, Preferences, and Objectives. Work in that order. A carefully tuned preference cannot repair missing participants, impossible capacity, or the wrong number of sessions.

Define the model

A person is normally assigned to one group in every session they attend. Capacity is enforced per group and session. If a facilitator is entered as a participant and fixed to a group, that facilitator also occupies capacity.

Use stable, recognizable names for people and groups. IDs exist behind the interface, but operators review schedules by their displayed names.

Add requirements sparingly

Requirements describe states the final schedule must satisfy:

• Immovable People fixes selected people to a group in selected sessions.
• Must Stay Together requires selected people to share a group.
• Must Stay Apart requires selected people to occupy different groups.

Required-rule violations are solver defects, not ordinary optimization trade-offs. More requirements also reduce the number of feasible schedules. Add one only when violating it would make the schedule unusable.

Add preferences and objectives

Preferences guide the solver toward better schedules but can have deviations. Available preferences include Repeat Encounter, Should Stay Together, Should Not Be Together, Attribute Balance, Attribute Sum, Encounters, and Group Visits.

Objectives tune broader optimization priorities such as maximizing new contacts. A larger weight changes relative optimization pressure; it does not turn a preference into a requirement.

Read Requirements, preferences, and objectives before combining several weighted targets.

Use a reliable setup order

1. Set the session count.
2. Name groups and enter their capacities.
3. Define only the attributes you genuinely need.
4. Add people, availability, and attribute values.
5. Add mandatory requirements.
6. Add weighted preferences.
7. Tune objectives last.
8. Open the Solver workspace and review Scope, Starting Point, Search, and Effort before running.

This order makes errors easier to locate. If a solve stops at validation, return to the model or the named constraint instead of changing unrelated solver settings.

Protect saved and temporary work

The normal landing-page Quick Setup bootstraps a saved workspace in this browser. Shared links remain temporary until you save a copy, while isolated guide examples deliberately use separate example storage. Read the workspace banner when it appears; it states whether the active scenario is saved, shared, or temporary.

Scenario activation uses revision checks. If the active scenario or its document revision changes during an asynchronous load or example-creation flow, GroupMixer reports a conflict rather than silently replacing newer work.

Grid editors may also protect unsaved local edits when you move between sections. Complete or discard that edit explicitly before navigating away.

Verify the scenario before solving

Before opening the Solver workspace, confirm:

• total capacity is sufficient for each session’s attendees;
• references point to people, groups, sessions, and attributes that still exist;
• required rules do not contradict one another;
• weighted targets are mathematically possible or intentionally aspirational;
• weights reflect actual priorities rather than arbitrary large numbers;
• the configured sessions match the periods you intend to publish.

Then run and improve a solve. If validation or solving still fails, start with Troubleshoot scenarios and solves.