In an installed z/OS environment that also includes IBM Power6 servers, the customer wants to consolidate both platforms onto a new z/OS server. Which method is used to establish the required capacity for this new z/OS server?

Introduction / Context:
This question is about capacity planning in an installed z/OS environment where a customer also runs IBM Power6 servers. The customer is considering consolidating AIX workloads onto a new z/OS server. To size the new server correctly, the planner must choose the most appropriate method for estimating the combined workload of existing z/OS and AIX systems so that the new z/OS configuration is neither undersized nor excessively oversized.

Given Data / Assumptions:

The customer already runs z/OS on System z hardware.
The customer also runs AIX workloads on Power6 servers.
The plan is to consolidate both environments onto a new z/OS server.
Standard IBM sizing tools like CP3000 are available for z/OS capacity planning.
The goal is to establish an accurate capacity requirement for the new consolidated z/OS server.

Concept / Approach:
Capacity planning on System z is typically done with tools such as CP3000, which model existing workloads and project required MIPS or MSU. However, when consolidating heterogeneous environments, the planner must consider workloads from both platforms. AIX workloads running on Power6 must be translated into equivalent load that can be added to the z/OS modeling results. The correct approach is to estimate the AIX load in comparable terms and then add that load to the CP3000 modeling results for the existing z/OS environment.

Step-by-Step Solution:
1. Collect performance and workload data from the existing z/OS system and run CP3000 to model current and future growth. 2. Measure or estimate the AIX workload on the Power6 servers in terms that can be mapped to System z capacity units. 3. Convert the AIX workload metrics into an equivalent z/OS capacity requirement using IBM guidelines or planning tools. 4. Add the converted AIX workload requirement to the CP3000 results for the existing z/OS environment. 5. Use the combined capacity requirement to choose the appropriate configuration for the new z/OS server.

Verification / Alternative check:
One way to verify the estimate is to compare projected utilization levels with IBM recommended headroom targets after consolidation. If the combined workload plus expected growth leaves reasonable spare capacity, the sizing is likely sound. You can also cross check with historical peak usage from both platforms to confirm that the proposed configuration would handle simultaneous peaks.

Why Other Options Are Wrong:
AD Tools do not replace proper workload based capacity modeling for consolidation projects.
Using CP3000 alone without adding the AIX workload ignores a major part of the future load and will typically undersize the new server.
Running the AIX workload temporarily in a z/OS LPAR just to observe load is impractical and does not represent normal production behavior. A systematic conversion of workload metrics is preferred.

Common Pitfalls:
A common mistake is to size the new z/OS server only for current z/OS workloads and treat the AIX consolidation as an afterthought. Another pitfall is failing to account for growth, seasonal peaks, batch windows, and service level agreements when combining workload estimates. Overreliance on rules of thumb without using formal tools like CP3000 can lead to inaccurate sizing.

Final Answer:
The capacity for the new z/OS server is established by estimating the AIX workload and adding that to the CP3000 sizing results for the existing z/OS environment.