---
sourceDocument: Zurich API Reference
sourceDocumentLink: https://www.servicenow.com/docs/r/zurich/api-reference

 Release :

    - zurich

ft:locale :

    - en-US

ft:publication_title :

    - Zurich API Reference

ft:clusterId :

    - crapiref

bundleId :

    - crapiref

workflow :

    - Creator


---

# Debugging business rules

# Debugging business rules {#ariaid-title1}

Release version: Zurich  
Updated July 31, 2025  
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## Summary of Debugging business rules

This guide explains how ServiceNow customers can effectively debug business rules using built-in tools and scripting techniques within the platform.
Debugging ensures business rules behave as expected by verifying conditions, queries, and variable values.
Show full answer Show less  

## Debugging tools

* **System Dictionary:** Access tables and their definitions via System Definition \> Dictionary to locate relevant data structures.
* **System Log:** Use System Logs \> System Log to record alert statements from business rules for troubleshooting.
* **Debug Business Rule (Details):** Found under System Diagnostics \> Session Debug, this tool shows whether business rule conditions are met and values set correctly.
* **Alert Messages:** Utilize system functions to print messages on the page, fields, or logs to monitor script execution.
* **Business Rule Examples:** Review existing scripts to find error message patterns or query techniques that can aid debugging.
* **GlideRecord Information:** Use GlideRecord syntax to query tables and verify data retrieval within scripts.

## Verifying variables and queries

To understand business rule behavior, verify that queries return expected records. For example, use `gs.addInfoMessage()` to display query results on the screen. Break down scripts into smaller parts if needed to isolate issues and confirm each piece functions properly before combining.

## Understanding table relationships

ServiceNow tables can extend others, meaning data might reside in parent or child tables. When querying, ensure you reference the correct table and sysid. For instance, to access information from an extended table like `sctask` and its parent `task`, query both tables using matching sysid values to retrieve fields such as work notes.  
Debugging business rules can be achieved with resources available in the ServiceNow product.

## 1. Tools

The first step in the process is to identify tools which will help you figure out what's
wrong.
{#r_DebuggingBusinessRules__table_ipc_pwl_jp__entry__2}

| Debugging tool | Description |
|-|-|
| System Dictionary | Navigate to System DefinitionDictionary. The dictionary provides a list of all tables within your instance and can be invaluable when trying to locate information. |
| System Log | Navigate to System LogsSystem Log. You can place alert statements in your business rule which can write information to the log. |
| Debug Business Rule (Details) | Navigate to System DiagnosticsSession DebugDebug Business Rule (Details). This debugging module displays the results business rules. Use this module to see if conditions are being met and values are being set as expected. |
| Alert Messages | There are several system functions that allow you to print messages to the page, the field or the log file. See [Scripting alert, info, and error messages](https://www.servicenow.com/docs/hyoDc4NE2oAqJTycAeqguw "You can send messages to customers as alerts, informational messages, or error messages."). |
| Business Rule Examples | Sometimes you can find what you're looking for in scripts others have written, including business rule error messages, or by building an OR query. |
| GlideRecord Information | This is the basic syntax used to query the database for information. See [Querying tables in script](https://www.servicenow.com/docs/Y~nD1FOgoLqUiVUAWKq6_w#c_UsingGlideRecordToQueryTables "Using methods in the GlideRecord API, you can return all records from a table, return records from a table that satisfy specific conditions, or return records that include a string from a single table or from multiple tables in a text index group."). GlideRecord also includes aggregation support. |
[Table 1. Debugging tools]

{#r_DebuggingBusinessRules__table_ipc_pwl_jp}

## 2. Variables

The next step is to gain some insight into the behavior of your business rule. For every
action except an insert, you will more than likely use a query to get your record(s).

    var rec = new GlideRecord('incident');
    rec.addQuery('active',true); 
    rec.query();
    while (rec.next()) {
     gs.print(rec.number + ' exists');
     }

To verify whether your query is actually returning records you can use
<var class="keyword varname">gs.addInfoMessage</var> to display information at the top of the screen.

    var rec = new GlideRecord('incident');
    rec.addQuery('active',true); 
    rec.query();
    gs.addInfoMessage("This is rec.next: " + rec.next());
    while (rec.next()) {
     gs.print(rec.number + ' exists');
     }

If your query returns no records you see the following:

    This is rec.next: false

Use this technique to verify every variable within your business rule contains expected
values.  
Tip:  
If necessary, break your script down into individual pieces and verify each piece works separate from the whole and then put them all back together one step at a time.

## 3. Locating information

The last step is to make sure you know where to find the information your rule is looking
for.

In the ServiceNow application, one
table can extend another table. This means when searching for information, you might need to
query the parent table for the extended table's sys_id to find what you seek.

A good example is the sc_task table, which extends the task table. The script below queries
the extended table (sc_task) for the current sys_id and then query the parent table (task)
for records with the matching sys_id, and then prints out the work notes field.

    var kids = new GlideRecord('sc_task');
    kids.query();
     
    gs.addInfoMessage("This is requested item number: " + current.number);
    gs.print("This is the requested item number: " + current.number);
     
    while (kids.next()) { 
     var parents = new GlideRecord('task');
     parents.addQuery('sys_id', '=', kids.sys_id);
     parents.query();
     
     while(parents.next()) {
      gs.addInfoMessage("This is task number: " + parents.number);
      gs.print("This is task number: " + parents.number);
      gs.addInfoMessage("These are the work notes: " + parents.work_notes);
      gs.print("These are the work notes: " + parents.work_notes);
      }
     
     }

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