ServiceNow Interview Questions
Q1. What is a table in ServiceNow?
A table stores records in ServiceNow database.
Example:
Incident records stored in incident table
Users stored in sys_user table
Q2. What are Base Tables?
Base tables are parent tables that contain common fields that can be inherited by other tables.
Example: Task table
Common fields: Number, State, Assignment Group, Assigned To
Q3. What is table hierarchy?
Tables can extend other tables.
Example:
task
├── incident
├── problem
├── change_request
Q4. What are Extended Tables?
Extended tables inherit fields from parent/base tables.
Examples: Incident, Problem, Change
All three extend the task table and automatically inherit its fields.
Q5. Why is task table important?
Most ITSM tables extend task, so they inherit:
Number
State
Assigned To
Work Notes
Priority
Q6. What is table extension?
Creating child tables from parent tables.
Example:
incident extends task
Q7. Difference between base table and child table?
Base Table Child Table
Parent Extends parent
Common fields Additional custom fields
Q8. What happens when table extends another table?
Child table inherits:
- Fields
- Business Rules
- ACLs
- Scripts
Q9. What is sys_id?
Unique 32-character ID for every record.
Q10. What is Dictionary Entry?
Defines field properties like:
- Type
- Length
- Default value
- Reference table
Table:
sys_dictionary
Q11. What is Dictionary Override?
Dictionary Override is used to modify field properties in child tables without affecting the parent table.
Using Dictionary Override, you can:
✔ Change label
✔ Make field mandatory
✔ Make the field read-only
✔ Set default values
Q12. Real-Time Scenario — Dictionary Override
Requirement: Change 'Assignment Group' label to 'Support Group' only in the Incident table.
Solution: Use Dictionary Override on the Incident table for the assignment_group field.
The Task table label stays unchanged. Only Incident users see 'Support Group'.
Q13. What is reference field?
Field referencing another table.
Example:
caller_id references sys_user
Q14. What is Reference Qualifier?
Reference Qualifier is used to filter reference field values shown in a dropdown.
Example: Show only groups whose name contains 'ITIL' in the Assignment Group field.
Reference Qualifier: name LIKE ITIL
Q15. Difference between Reference and List field?
Reference List
Single record Multiple records
Q16. Which tables extend task?
- incident
- problem
- change_request
- sc_task
Q17. Why do incidents have work notes automatically?
Because incident inherits from task
Q18. Can we create custom table extending task?
Yes.
Q19. Difference between Task and CMDB table?
Task Table CMDB Table
Stores tickets Stores infrastructure items
Q20. User table name?
sys_user
Q21. Group table name?
sys_user_group
Q22. Role table name?
sys_user_role
Q23. Many-to-many relationship between users and groups table?
sys_user_grmember
Q24. What is itil role?
Common ITSM role allowing access to ITSM applications.
Q25. Difference between UI Policy and Client Script?
UI Policy Client Script
No scripting needed Requires scripting
Simple form logic Complex logic
Q26. What is Data Policy?
Enforces data validation at database level.
Works for:
- UI
- Import Sets
- Web services
Q27. Difference between UI Policy and Data Policy?
UI Policy Data Policy
UI only Server/database level
Q28. What is Dictionary Override?
Overrides inherited field properties in child table.
Q29. What is Import Set?
Temporary staging table for imported data.
Q30. What is Transform Map?
Maps import set data to target table.
Q31. What is Coalesce field?
Used to identify matching records during import.
Q32. Difference between Insert and Update in transform?
Insert Update
Creates new record Updates existing
Q33. How email notification works in ServiceNow?
Triggered by:
- Events
- Conditions
- Flow Designer
Q34. Notification table?
sysevent_email_action
Q35. What is inbound email action?
Creates or updates records from incoming emails.
Q36. How incident created from email?
Using inbound email action.
Q37. Difference between Flow and Subflow?
Flow Subflow
Main automation Reusable component
Q38. Can Flow Designer replace Workflow?
Mostly yes in modern implementations.
Q39. What triggers Flow Designer?
- Record creation
- Update
- Scheduled trigger
- API trigger
Q40. Before Business Rule use case?
Modify record before saving.
Q41. After Business Rule use case?
Trigger actions after save.
Q42. Async Business Rule use case?
Background processing.
Example:
- Notifications
- Integrations
Q43. What is purpose of Display Business Rule?
Send server data to client side.
Q44. What is onLoad Client Script?
Runs when form loads.
Q45. What is onChange Client Script?
Runs when field value changes.
Q46. What is onSubmit Client Script?
Runs before form submission.
Q47. Difference between current and previous?
current previous
Current record Old record before update
Q48. What is GlideSystem?
Server-side utility API (gs).
Q49. What is gs.info()?
Prints logs in system log.
Q50. What is GlideAggregate?
Used for aggregate operations like:
- COUNT
- SUM
- AVG
Q51. ACL evaluation order?
- Roles
- Conditions
- Scripts
Q52. Difference between table ACL and field ACL?
Table ACL Field ACL
Entire table access Specific field access
Q53. What is Identification Rule?
Prevents duplicate CI creation.
Q54. What is Reconciliation Rule?
Controls which data source can update CI.
Q55. What is CSDM?
Common Service Data Model.
Standard framework for CMDB/service mapping.
Q56. What is Service Portal?
Frontend portal for users.
Q57. Difference between Platform UI and Service Portal?
Platform UI Service Portal
Agent/admin use End-user use
Q58. Best practices for Update Sets?
One feature = one update set
Avoid default update set
Preview before commit
Q59. What if update set misses changes?
Manually add records or retrieve update sets.
Q60. Why instance becomes slow?
- Heavy scripts
- Unoptimized queries
- Too many synchronous BRs
- Large data loads
Q61. How to improve performance?
- Use indexes
- Use async processing
- Optimize GlideRecord
- Avoid nested queries
Q62. Incident not assigning automatically. What will you check?
- Assignment rule conditions
- Execution order
- Business rules
- Data values
Q63. Notification not triggering. What will you check?
- Event generation
- Notification condition
- User email
- Mail logs
Q64. SLA not attaching. What will you check?
- SLA conditions
- Start condition
- Task table
- SLA definition
Q65. Client Script not working in Workspace. Why?
Some classic UI scripts behave differently in Workspace.
Q66. Module vs Table name
VERY COMMON TABLE QUESTIONS
Module Table
Incident incident
Problem problem
Change change_request
User sys_user
Group sys_user_group
Role sys_user_role
CMDB cmdb_ci
Knowledge kb_knowledge
SLA task_sla
Catalog Item sc_cat_item
Request sc_request
RITM sc_req_item
Catalog Task sc_task
Dictionary sys_dictionary
Business Rule sys_script
Client Script sys_script_client
UI Policy sys_ui_policy
ACL sys_security_acl
Notification sysevent_email_action
Update Set sys_update_set
Q67. What is Incident Management in ServiceNow
Incident Management is used to restore normal service operation as quickly as possible and minimize business impact.
Q68. Difference between Incident and Problem?
Incident Problem
Restores service quickly Finds root cause
Reactive Reactive + Proactive
Short-term fix Permanent fix
Stored in incident table Stored in problem table
Example:
VPN not working → Incident
Root cause analysis for recurring VPN failures → Problem
Q69. What are major fields in Incident table?
- Number
- Caller
- Category
- Subcategory
- Assignment Group
- Assigned To
- Priority
- State
- Impact
- Urgency
- Configuration Item (CI)
Q70. How is Priority calculated?
Priority is calculated using:
Impact
Urgency
Example:
High Impact + High Urgency = Priority 1
Q71. Difference between Client Script and Business Rule?
Client Script Business Rule
Runs on browser Runs on server
Form validation/UI changes Database/backend logic
Faster UI interaction Data processing
Q72. How do assignment rules work?
Assignment Rules automatically assign incidents to appropriate groups/users based on conditions like category, CI, location, etc.
Q73. What is Problem Management?
Problem Management identifies root causes of recurring incidents and prevents future occurrences.
Q74. What is Known Error?
A problem with identified root cause and workaround is called Known Error.
Q75. Relationship between Incident and Problem?
Multiple incidents can be linked to one problem record.
Q76. What is RCA?
RCA means Root Cause Analysis.
Common techniques:
5 Why Analysis
Fishbone Diagram
Q77. Types of Change in ServiceNow?
Change Type Meaning
- Normal Requires CAB approval
- Standard Pre-approved low risk
- Emergency Urgent high priority
Q78. What is CAB?
CAB (Change Advisory Board) reviews and approves risky changes.
Q79. Difference between Normal and Standard Change?
Normal Standard
Requires approval Pre-approved
Risk assessment needed Low-risk repetitive
More workflow Simple workflow
Q80. What happens after change closure?
Post Implementation Review (PIR) can be conducted to validate success/failure.
Q81. What are change states?
Typical lifecycle:
New → Assess → Authorize → Scheduled → Implement → Review → Closed
Q82. Difference between Request and Incident?
Incident Request
Something broken User asking for service
Reactive Planned
Example: VPN issue Example: Laptop request
Q83. Difference between REQ, RITM, SCTASK?
Record Purpose
- REQ Parent Request
- RITM Requested Item
- SCTASK Fulfillment task
Example:
Laptop Request:
REQ0010001
RITM0010001
SCTASK0010001
Q84. What is Record Producer?
A Record Producer creates records in a target table from Service Portal.
Q85. What is SLA?
SLA defines expected resolution/response time for tasks.
Q86. Difference between Response SLA and Resolution SLA?
Response SLA Resolution SLA
Time to first response Time to resolve issue
Q87. What are SLA conditions?
- Start Condition
- Pause Condition
- Stop Condition
- Cancel Condition
Q88. When does SLA pause?
Usually when incident state becomes:
- On Hold
- Awaiting User
Q89. What is CMDB?
CMDB stores Configuration Items (CI) and their relationships.
Q90. What is CI?
Configuration Item is any infrastructure/service component like:
- Server
- Database
- Application
- Router
Q91. What is Discovery?
Discovery automatically identifies devices/services and populates CMDB.
Q92. Why are CI relationships important?
They help in:
Impact Analysis
Root Cause Analysis
Dependency Mapping
Official docs mention Incident Management heavily uses CMDB/CSDM tables and CI relationships.
Q93. What is Knowledge Management?
It stores reusable solutions and documentation.
Q94. Benefits of Knowledge Articles?
Faster resolution
Self-service support
Reduced ticket volume
Q95. What is Knowledge Workflow?
Draft → Review → Publish → Retire
Q96. Difference between Workflow and Flow Designer?
Workflow Flow Designer
Legacy Modern
More scripting Low-code
Older UI Easy UI
Q97. Why use Flow Designer?
To automate:
- Approvals
- Notifications
- Task creation
- Integrations
Q98. Types of Business Rules?
- Before
- After
- Async
- Display
Q99. Difference between GlideRecord and GlideAjax?
GlideRecord GlideAjax
Server-side DB access Client-server communication
Q100. What is gs.eventQueue()?
Used to trigger events and notifications.
Syntax:
gs.eventQueue('event.name', current, parm1, parm2);
Q101. What is ACL?
ACL controls access to records/fields.
Checks:
- Role
- Condition
- Script
Q102. Difference between role and ACL?
Role ACL
Gives permission Enforces permission
Q103. Difference between Report and Dashboard?
Report Dashboard
Single visualization Collection of reports
Q104. Types of Reports?
- Pie
- Bar
- List
- Pivot
- Time Series
Q105. User says VPN is slow. What will you do?
Flow:
- Create Incident
- Check CI
- Check related outages/problems
- Assign to network team
- Apply SLA
- Resolve & close
Q106. Daily recurring issue happening. What approach?
- Create Problem
- Perform RCA
- Create Known Error
- Raise Change Request
- Implement permanent fix
Q107. SLA breached frequently. What will you check?
- SLA conditions
- Assignment delays
- Incorrect pause states
- Workflow issues
- Group workload
Q108. What is Display Value vs Actual Value?
Display Value Actual Value
Human readable Stored DB value
Example:
User Name displayed
sys_id stored internally
Q109. What is Dot Walking?
Accessing fields from referenced tables.
Example:
current.caller_id.email
Q110. What is Encoded Query?
Compressed query format used in GlideRecord/filtering.
Example:
active=true^priority=1
Q111. Difference between gs.addInfoMessage and gs.addErrorMessage?
Info Message Error Message
Success/info Validation/error
Q112. What is Auto Numbering?
Automatic record number generation like:
INC0010001
CHG0010001
Q113. What is Reference Qualifier?
Filters reference field choices dynamically.
Q114. What is Domain Separation?
Separates data between different customers/business units
Q115. What is Import Set Row Error?
Failed import records stored for troubleshooting.
Q116. Difference between getValue() and getDisplayValue()?
getValue() getDisplayValue()
Actual DB value Displayed readable value
Q117. What is ATF in ServiceNow?
Automated Test Framework used for automated testing.
Q118. Business Rule causing duplicate records. How will you debug?
- Check recursive updates
- Verify current.update()
- Debug logs
- Check async rules
Q119. Why should current.update() be avoided in Business Rule?
Can cause recursive loops and performance issues.
Q120. What happens if multiple Business Rules run together?
Execution order determines behavior.
Q121. Difference between setValue() and direct assignment?
setValue() Direct Assignment
Recommended Simpler
Example:
gr.setValue('state', 2);
Q122. What is g_form?
Client-side API for form manipulation.
Q123. What is g_user?
Client-side API containing logged-in user details.
Q124. What is GlideSession?
Stores session information for logged-in user.
Q125. What is Script Action?
Runs server-side script when event triggered.
Q126. Difference between Global and Scoped Application?
Answer:
Global Scoped
Accessible everywhere Restricted scope
Q127. What is Application Menu and Module?
Navigation structure in left menu.
