Scenario Editor

Use the Scenario Setup sections

Scenario Setup opens the last section you used; a new workspace normally opens People. The sidebar groups the editor into Model, Requirements, Preferences, and Objectives.

Model

A person is assigned once in every session included in their Session Participation. The group must have room for that assignment, and a nonzero minimum occupancy adds a lower bound for the group.

Add or scaffold groups

Use Add Group to enter one named group. Use Scaffold groups to calculate a set from Number of groups or People per group.

Scaffolding does not apply immediately. Select Preview changes, review additions, removals, capacity changes, and blockers, then select Apply scaffolding. Existing group identities are retained by position. A group cannot be removed while a manual constraint still references it.

In List or CSV view, the group columns are Group name, Default capacity, Default min, Session capacities, and Session minimums. Session arrays use JSON in CSV mode, for example [6,6,0].

Define attributes and people

Attribute Definitions supports Cards, List, and CSV. In CSV mode, separate possible values with |.

The People section has three entry paths:

• Add Person for one person at a time;
• List or CSV for bulk editing names, Sessions, and attribute columns;
• Import Data for a Names list, Spreadsheet CSV, or Zoom breakout CSV.

Names list and Spreadsheet CSV replace the current People collection after confirmation. Zoom CSV merges by email and adds or updates zoom_email and zoom_room attributes.

List and CSV edits are drafts. Select Apply changes to save them or Discard changes to revert them. If you leave with a draft, GroupMixer offers Stay, Discard and leave, and Apply and leave.

Add requirements, preferences, and the objective

Requirements must hold in a returned schedule:

• Fixed Placements assigns selected people to one target group.
• Keep Together puts all selected people in the same group.
• Keep Apart separates every selected pair.

Preferences can have violations and add weighted cost:

• Prefer Together
• Prefer Apart
• Balance Attributes
• Attribute Totals
• Encounters
• Group Visits

Objectives are global schedule-quality goals:

• Maximize Contacts rewards distinct pairs meeting at least once.
• Avoid Repeats penalizes pair meetings above its global threshold using the selected linear or squared cost.

Set an objective weight to 0 to remove its influence from the score.

Scope selectors use a consistent rule: All includes current and future people, groups, or sessions. Selecting every item individually creates a fixed current list; later additions are not included automatically.

Read Requirements, preferences, and objectives for the measurement used by each family.

Use automatic attribute distribution

Under Balance Attributes, the Auto distribute and Allocation overview panels start collapsed so the constraints table stays visible. Expand either panel when you need it. The shared Weight legend in Allocation overview applies to every attribute shown.

Select Auto distribute in the page actions to create live targets for every current group and session for one attribute. Choose the Attribute, Weight, and Mode, then select Enable auto distribution. If manual Balance Attributes constraints exist for that attribute, confirm their replacement first.

Enabling it replaces manual Balance Attributes rows for that attribute. While active, targets recalculate when people, attendance, values, groups, capacities, or sessions change. Unavoidable rounding differences rotate across sessions instead of staying with the same group, and identical session targets appear as one multi-session constraint. Generated rows remain visible in Cards and List as read-only Auto managed constraints; editable CSV includes manual rows only. Turn off keeps the current targets and makes the generated rows editable.

Review versions and recover earlier work

Select Open scenario versions and recovery in the workflow bar. The local status strip confirms the current version, loaded history, and browser availability. Use All changes to browse exact revisions in a date-grouped timeline or Named versions to focus on restore points you named.

On desktop, select a revision or named version in the history list to inspect it alongside its scenario summary and differences from the current scenario. On a narrow screen, the same selection opens a focused detail view; use Back to versions to return without losing the history context.

From the detail view, you can fork the selected version as a separate scenario, revert the current scenario as a new change, or give an exact revision a recognizable name. Named versions reference existing history rather than copying the scenario. Reverting preserves later history and saved results.

The Diagnostics & recovery tab reports local durability and document problems, offers supported repairs, and can download a raw recovery copy. These history and recovery operations work without an account or cloud connection.

Generate the schedule

With basic controls, select Generate Groups in the workflow bar. GroupMixer runs the recommended plan and opens the result.

With Advanced controls enabled in Editor preferences, open Solver to review Scope, Starting Point, Search, and Effort before running. If generation reports Scenario needs changes, follow Review groups, Review people, or Review constraints in the notification. See Run and improve a solve and Troubleshoot scenarios and solves.