What is SP upgrade:
A Support Package contains a collection of BUG fixes. After you have imported a Support Package, you must perform the Modification Adjustment using transaction SPAU. Basis responsiblity to maintain the system at latest level or N-1 level .
Prerequisites:
- Before starting the SP upgrade maintain the kernel at latest level. or skip the kernel part while generating stack for SP upgrade.
- Make sure to put the maintenance certificate before SP upgrade.
- Delete the old spool number in SAP system before start the SP upgrade.
- Maintain minimum 48 GB free in Database to run SUM tool.
- Before starting read the SUM manual for quick action.
- Note: SUM tool have the option to upgrade both ABAP + JAVA stack at same time.
Step 1:Download SUM latest version from service market place In my case am using SUM 1.0 SP06(Latest is SP8)
Please make a note of HTTP Listening port number. In my case -4239
Step 2: Start SUM from browser using hostname and port 4239.
Step 3: As stated earlier we can upgrade ABAP+JAVA at the same time to reduce the downtime.
Fill SIDADM password. 
Step 4: We have successfully generated stack.XML file before start the SP upgrade and put into EPS\In folder and specify as same below.
Step 5:Refer SAP note 1707161 and do the needful i.e update the keyword .
Step 6: Complete the initialization part and click next.
Step 7:Provide DDIC[000 Client] user password to extract the system information
Step 8: SPAM version is too low to proceed further so we have imported latest version of SPAM. 
Step 9:Currently extraction phase running on. SAP recommended notes missing from our system, so first implement the below listed SAP notes to proceed . 
Step 10: . 
In this configuration phase we can set the number of parallel process should run during our SP upgrade.
Step 11: Currently configuration part running on. it will give the system information.
At this phase, request developer to capture the SPAU and SPDD correction in transport number and fill the same below as well.
Now here ABAP phase completed successfully. we will go for JAVA part.
Step 13: Provide necessary java admin & SAP* passwords.
java got completed successfully.
Step 14: checks phase run for both ABAP+JAVA.
Preprocessing phase-Shadow system to be created end of preprocessing phase.
Execution phase- upgrade the shadow system first and check if SP upgrade is successful?
Postprocessing phase-copy the shadow instance ie upgraded system to our target system.
We have successfully completed SP upgrade by using SUM