SCCM Software Update Deployment flow

The SCCM clients receive their SUP/WSUS settings as a local policy on the clients,

Scan gets initiated as per configured schedule and happens on base of update GUID. Location services looks for our nearest SUP. This also can be checked in windowsupdate.log

When scan is completed. ScanAgent reports that the scan is complete and records the results of the scan in the updatestore. Information can be checked in updatestore.log

Client sends result of scan cycle through status massages with topic ID 501 and 500 to MP and site server for each the update that are missing on machine. This can be checked in statemassage.log

Once all this process completes updates evaluation gets start by receiving policy for applicable updates. Scan gets initiated for to have latest scan data update applicability and report status, This information can be checked in updatedeployment.log

Client Retrieve needed update components through CIAssignment and then SDM agent checks what binaries are included in the patch package,

After that patches get started to download and information can be checked in Patchdownloader.log

Once patches get downloaded windows update agent Apply and install the updates, this can be checked in Updatehandler.log

Once the installation is completed, Scan for update status gets start to record update installation compliance and sent to site server through WMI.

Cheers...