Please have a look at the roadmaps at Service Market place
S/4 HANA on Premise https://websmp101.sap-ag.de/~sapidb/012002523100006634812015E.pdf
S/4 HANA Cloud https://websmp101.sap-ag.de/~sapidb/012002523100005148472016E.pdf
In this you have secion for maintenace management.
You can also refer roadmap for Asset Management that includes S/4 HANA as well as other related products.
https://websmp101.sap-ag.de/~sapidb/011000358700000125612012E.pdf
Best Regards
Hemant