We are early customers of BW7.4 SP3 ( Nov, 2013) and i would like to highlight issues where we faced. I checked the upgrade issues from other friends and the issues are not same as like them and so thought to post them.
1) Reporting:Reports using BEX CMOD will fail as we might have wrote the code : DATA : LOC_VAR_RANGE LIKE RRRANGEEXIT.
In BW7.4, you have to use TYPE instead of LIKE. After replacement , code started working .
After we solved the issue, SAP released Note 1823174 for the same issue.
2)DSO Activation Issue: If you changed records in PSA, then ODS activation will fail if we do both original and error DTP request at one shot. We need to do one after another.
3) Open Hub loading: If you are using open hub earlier, then immediately after upgrade, records sent will be zero. Please execute the programme SAP_FACTVIEWS_RECREATE to solve the issue. This program is a part of the post upgrade activity which you see in /asu/upgrade. But some times it could happen that your basis team will not inform you about it.
4) Infoset Reporting: Reports on Infoset will not working . Please execute the report RSQ_ISET_MASS_OPERATIONS to solve the issue.
5)Master data reporting: Reports on master data like 0employee etc will not be working. Please implement the oss notes:1910472,1906848 ,1852827 .
6) Do you have external systems which will feed from BW systems?. then they also will not work. SAP introduced gateway concept so you are forced to maintain the the external system IP adress in table : SAPFTP_SERVERS.
7) BO Reporting : SAP mentioned in PAM that BO4.0 SP6 is compatible with BW7.4 SP3 in PAM. But BICS reports have issues as the prompt values are not coming as per expectations. We are now upgrading to BI4.1 to solve the issues.
8) Authorizations : After the upgrade, you have to do migration of authorizations so that all authorization objects are active again. In that process, we will face issues due to * authorizations . Please follow the OSS note to solve the issue 1917777.
9) DB connect: We have to install the DB client latest as earlier DB client will not support .
10) UD Connect: We are using the portal for UD connect. You need to ensure that portal is compatible with BW7.4 after upgrade. PAM will have that information.
Finally it is always advised to send a OSS message to SAP before you start the upgrade as some times one component/ patch will make too much differences and your project plan will go for a toss due to this. Keep all dependences and interfaces in scope for the plan.