Support Package pre-requistis accross different landscapes

Question

I am struggling with which landscape but be patched before another since adding PI 711 into the mix.
I am supporting ECC6 EHP4 with NW701, BI 70 at Netweaver 70, Solution Manager 70 Ehp1 and now PI 71 ehp1.
I have been told PI must lead all other landscapes support package level but with it being at a later version of Netweaver than all other landscapes it is a far comparison or does it already lead them?
My immediate need is to begin planning for a support package project on the ECC6 EHP4 landscape in the fall.  Since this landscape was last patch, about one year ago we add the PI landscape.
It is a pretty safe bet I will be struggling with this same question in about 6 months when I start looking at a BI support package project.
Any help that could be provided on this would be most appriciated.
Bill

Answer 1

I think we need to understand more why you feel certain systems need to be patched first or in a certain order
- from what you say there must be technical concerns across more than one product area
Perhaps it could be that --->
Generally systems that interact with one another should be on the same BASIS level and SP stack - the general rule of thumb
Products such as SLD definately have to be on systems with equivalent or higher BASIS version and SP stack than systems
they interact with because the content created for a Netweaver 700 SLD
may not be able to cope data supplier information from a Netweaver EHP1 system (this also raise other concerns regarding
exporting data between SLDs - again equivalency - or higher for target system is recommended, sometimes with SLD lower BASIS version source systems may have limited export options as well)
Products such a Solution Manager also as a rule of thumb have to be on equivalent or higher BASIS version or SP levels
than the systems they interact with
But PI also may have similiar concerns because they manage communication between systems e.g business systems
However lets take say Payroll in ECC without any ESS or Legacy Systems, ALE
- totally standalone payroll system - the only rules that apply there are that it works, has the latest fixes and required legal changes and follows a recommended stack - no BASIS equivalency level between other systems may exist in order for payroll to carry out its purpose
Does this help clarify further ?
Best wishes
Stuart