How to deploy tss and many other products without jcl changes, no new sysres etc
Use IDCAMS to define symbolic alias datasets
Extended Alias Supporte.g.
ALIAS --------- HLQ.TSS.ALIAS.CAKOLINK
IN-CAT --- CAT.ASDF
ASSOCIATIONS
SYMBOLIC-HLQ.TSS.&VERSTSS..&DATETSS..CAKOLINK
RESOLVED-HLQ.TSS.R15.D190427K.CAKOLINK
use such alias datasets in jcl e.g. cics dfhrpl, TSO, ISPF Libdef
but not in APF,LPA, linklist - use symbols there HLQ.TSS.&VERSTSS..&DATETSS..CAKOLINK , because aliases cannot be resolved there
define in ieasymxx &VERSTSS, &DATETSS Symbols
So you can use same jcl in different lpars and point with symbols to different tss levels , versions.
If you Steplib to such a Dataset the alias is resolved when the jobstep starts. So the Conversion System does not matter. This is not the case if you use an initiator with syssym=allow and put the dataset with symbols into jcl.
To fallback to an older version simply change the symbol and ipl. Or if the product allows restarts IEASYMUP Util is helpful
T.