The Scenario
The change request for a major network switch replacement is sitting in the approval queue. Before the change manager signs off, she needs a blast radius assessment: which other CIs in the CMDB depend on that switch? She has a Google Sheet with 20 server CI sys_ids in column A — all the servers that route through the switch. She needs columns B and C to show the downstream dependent CIs for each server before the approval meeting in two hours.
The bad version:
- Open ServiceNow CMDB, search for the first CI sys_id, navigate to the Relationships tab, expand the "Depends on" and "Used by" sections, make note of the downstream CIs.
- Click through each downstream CI to get its name and class.
- Repeat for all 20 servers.
- Compile the dependency information into the sheet in a format the change manager can actually read in the meeting.
Two hours is not enough time to do this manually for 20 CIs, especially when each one might have 5 to 15 downstream dependencies.
The Easy Way: One Prompt in SheetXAI
SheetXAI is an AI agent that lives inside your Google Sheet. It reads the CI sys_id column, queries the ServiceNow CMDB relationship API for each, and writes the dependent CI names and classes into the blast radius sheet.
For each CI sys_id in column A, get all downstream dependent CIs from the ServiceNow CMDB and list their names and classes in columns B and C
What You Get
- Downstream dependent CI names and classes written into columns B and C for each server in column A
- Relationship type included so you can distinguish "Depends on" from "Used by" dependencies
- CIs with no downstream relationships receive "NO DEPENDENCIES" in column B
- The full map runs in one batch — no CI-by-CI navigation
What If the Data Is Not Quite Ready
You need the relationship type (Depends on vs Used by) in a separate column for the impact report
The change manager's impact report template has separate columns for each relationship type.
For each CI sys_id in column A, get all CMDB relationships from ServiceNow and write the related CI name in column B, relationship type in column C, and related CI class in column D
Some of the downstream CIs are themselves servers with further dependencies
You want a two-level dependency chain, not just one level.
For each CI sys_id in column A, get the first-level downstream dependent CIs from ServiceNow CMDB and write their names and classes in columns B and C, then for each first-level CI get its own downstream dependencies and list them in columns D and E, noting the total dependency depth in column F
You want to filter out non-production CIs from the blast radius
Staging and development CIs should not inflate the impact estimate.
For each CI sys_id in column A, get all downstream dependent CIs from the ServiceNow CMDB, filter to only those with environment "Production," and write the remaining CI names and classes into columns B and C, with the count of excluded non-production dependencies in column D
Full kill chain: pull two levels, filter production, flag business-critical CIs, and summarize
For each CI sys_id in column A, pull all downstream CMDB dependencies in ServiceNow to two levels, filter to production environment only, flag any CI marked as business-critical in column E, write CI name, class, relationship type, and criticality flag into columns B through E, and add a summary row at the bottom showing total impacted CIs and the number of business-critical ones
The change manager has a full blast radius picture before the approval meeting starts.
Try It
Get the 7-day free trial of SheetXAI and open the Google Sheet with your server CI sys_id list, then ask it to map the full ServiceNow CMDB dependency chain before the change review. For populating the CMDB with new CIs, see the bulk-populate-cmdb spoke or return to the ServiceNow hub.