Decisions and Parallel Paths

Not every process follows a straight line. Nembl's workflow builder supports decision points that choose different paths based on conditions, and parallel paths that let multiple steps happen at the same time.

Decision Phases

A Decision phase is a branch point in your workflow. It evaluates one or more conditions and routes the request down the appropriate path.

When to Use a Decision

Use a Decision phase when the next step depends on something about the request. Common examples:

• Approval routing — If the purchase amount is over $1,000, send to director approval. Otherwise, send to manager approval.
• Category routing — If the request category is "Hardware," send to the IT Hardware team. If "Software," send to IT Software.
• Priority handling — If priority is Urgent, skip the queue and assign immediately.

Setting Up a Decision

1. Add a Decision phase to the canvas from the toolbar.
2. Give it a descriptive name (for example, "Check Purchase Amount" or "Route by Category").
3. Create transitions from the Decision phase to each possible next phase.
4. Configure the conditions for each outgoing path.

Configuring Conditions

Each outgoing transition from a Decision phase has a condition that determines when that path is taken. Conditions are based on the request data:

• Field comparisons — Check if a form field equals a value, is greater than a number, or contains specific text.
• Status checks — Check the current state of the request.
• Logical operators — Combine multiple conditions with AND or OR.

For example, a transition labeled "High Value" might have the condition: Purchase Amount > 1000.

Default Paths

Every Decision phase should have a default path — the transition that is followed when none of the other conditions match. This prevents requests from getting stuck at a decision point. The default path is typically the last outgoing transition and is often labeled "Default" or "Other."

If you do not set a default path and a request does not match any condition, the workflow will pause and flag the issue for an administrator.

Multiple Conditions

You can chain conditions for more complex routing. For example:

• Path 1: Category is "Hardware" AND Amount is greater than $500
• Path 2: Category is "Hardware" AND Amount is $500 or less
• Path 3: Category is "Software"
• Default: Everything else

Parallel Phases

A Parallel phase splits the workflow into multiple paths that run simultaneously. All paths must complete before the workflow moves on.

When to Use Parallel Paths

Use Parallel phases when multiple steps can happen at the same time and do not depend on each other. Examples:

• Employee onboarding — Set up the workstation, create email accounts, and prepare onboarding documents all at once.
• Vendor evaluation — Run a technical review, a financial review, and a reference check simultaneously.
• Event planning — Book the venue, arrange catering, and send invitations in parallel.

Setting Up a Parallel Phase

1. Add a Parallel phase to the canvas. This creates the fork point where paths split.
2. Create transitions from the Parallel phase to each path's first phase.
3. Build out each path with its own phases and transitions.
4. Connect the last phase of each path to a common join point.

How the Fork and Join Work

• Fork — When the workflow reaches the Parallel phase, it starts all outgoing paths at the same time. Each path runs independently.
• Join — The join point waits until every parallel path has completed. Only when all paths reach the join does the workflow continue to the next phase.

This means the total time for the parallel section is determined by the slowest path, not the sum of all paths.

Nesting Parallel Paths

You can put Decision phases inside parallel paths, or nest parallel phases within other parallel phases, though this adds complexity. Keep it simple when you can.

Tips for Complex Workflows

• Keep decisions close to the top. Route requests early in the workflow so each path is as focused as possible.
• Always set a default path. Prevent requests from getting stuck.
• Limit parallel paths to what truly runs simultaneously. If one task usually depends on another's result, keep them sequential.
• Test edge cases. Submit test requests that hit every branch of your decisions to make sure all paths work correctly.
• Document your conditions. Use clear labels on decision transitions so anyone looking at the workflow can understand the logic at a glance.