You can automate the progression of matter stages based on case criteria using the Process Builder. In this walkthrough we will build a process that automatically changes a matter's stage to Trial. 

How to Automate Matter Stage Progression

1. Create Process

1. Navigate to Setup > Process Builder.  
2. Select New. 
3. Complete the following fields:
   • Process Name: Change Matter Stage to Trial
   • API Name: Change_Matter_Stage_to_Trial
   • Description: Changes Matter Stage to Trial
   • This process starts when: A record Changes
4. Save.  You are taken to the Process Builder UI.

2. Add Object 

1. Select + Add Object.
2. Complete the following fields:
   
   • Object: Matter
   • Start the process: when a record is created or edited.
3. Save. 

3. Add Criteria 

1. Select + Add Criteria. 
2. Complete the following fields: 
   • Criteria Name:  Matter Status Field Update
   • Criteria for Executing Actions: Conditions are met 
   • Field: Matter Status
   • Operator: Equals
   • Type: Picklist
   • Value: Deferred
3. Save. 

4. Add Action

The following action sets the matter record's status to Deferred and updates the stage using its unique ID. Stage IDs can be found in the URL of a Matter Stage record. 

/litify_pm__Matter_Stage__c/a0U6g000000MoJ1EAK/view

1. Select + Add Action.
2. Complete the following fields:
   • Action Type: Apex
   • Action Name: Set Stage to Trial
   • Apex Class: Change Matter Stage
3. Select + Add Row. 
4. Complete the following fields:
   • Field 1:  matterIds
   • Type 1: Formula
   • Value 1:  [litify_pm__Matter__c].Id
   • Field 2: stageTemplateIds
   • Type 2: ID
   • Value 2: a0U6g000000MoJ1EAK
5. Save.

The string for Value 2 depends upon the unique ID of a Matter Plan's Stage.