Step 1. Plan the details

If installing for the first time (not upgrading), understand installation basics.
Reference information: Learning about z/OS.
If upgrading, understand changes in the new release that affect installing.
Reference information: Summary of changes for the z/OS installation planner.
Choose the software installation method. Choices are:
- ServerPac (entitled)
- CBPDO (entitled)
- SystemPac (additional charge)
- Others at additional charge
- None if sharing or cloning
Reference information:
- ServerPac, CBPDO, and SystemPac: Choosing an installation package for installing z/OS
- Other fee-based methods: http://www.ibm.com/services/
- Sharing or cloning: Installing z/OS without using an installation package
Choose the software delivery method. Choices are:
- Tape
- DVD
- Internet
Reference information: Choosing the delivery medium: tape, DVD, or Internet.
Identify driving system hardware and software requirements.
Reference information: Preparing the driving system.
Choose the target system hardware to install or upgrade.
Reference information: Identifying hardware requirements for the target system and Hardware requirements for running z/OS V2R1.
Choose the target system software to install.
Possible types of software are z/OS® optional features, IBM® middleware, IBM applications, and ISV products.

Reference information: Choosing software products to install and identifying requisites and Software requirements for running z/OS V2R1.
Choose the target system JES level.
z/OS V1R13 is the last release to support a staged migration for JES2 and JES3. Starting in z/OS V2R1, customers need to migrate to all elements of z/OS at the same time, including JES2, JES3, or both.

Reference information: Using JES and SDSF with z/OS V2R1.
If upgrading, identify migration actions for z/OS.
Migration actions, or tasks, fall into three categories based on when they should be performed:
- Before installing (performed on the old system)
- Before first IPL (performed on the new system before the first IPL)
- After first IPL (performed on the new system after the first IPL)
Two migration actions in the "before installing" category are worthy of note here:
- Identifying coexistence and fallback service.
  Coexistence service (installed on old systems that share resources) allows the new system to coexist (share resources) with old systems. (Examples of shared resources are JES spools, RACF® databases, user catalogs, and ISPF profiles.)
  
  Fallback service (installed on the system from which you are migrating) allows you to back out of the installation, if necessary.
- Reviewing hardware and software PSP buckets for changes to planning information.
Reference information:
- All of z/OS Migration. Note that within the publication, the three possible timings are labeled "before installing z/OS V2R1", "before the first IPL of z/OS V2R1", and "after the first IPL of z/OS V2R1".
- Apply coexistence and fallback PTFs in z/OS Migration
- Review PSP buckets in z/OS Migration
If upgrading, identify migration actions for IBM middleware, IBM applications, and ISV products.
Reference information: IBM product publications and ISV publications.
If installing for the first time, identify customization needed on the new system.
This customization will allow you to exploit (make productive use of) the z/OS functions necessary to accomplish your enterprise's goals.
Reference information:
- z/OS publications that have customization information, such as z/OS MVS Initialization and Tuning Reference and z/OS Infoprint Server Customization. z/OS publications are at the z/OS Internet Library (http://www.ibm.com/systems/z/os/zos/bkserv/).
- Product-specific publications that have customization information, such as .
- Preparing for customization and test.
If upgrading, identify postmigration customization needed on the new system.
Examples of postmigration customization tasks are adding devices, upgrading the network, and taking advantage of (exploiting) release enhancements.
Reference information:
- z/OS publications that have customization information, such as z/OS MVS Initialization and Tuning Reference and z/OS Infoprint Server Customization. z/OS publications are at the z/OS Internet Library (http://www.ibm.com/systems/z/os/zos/bkserv/).
- Product-specific publications that have customization information, such as .
- Preparing for customization and test.
Identify test activities. Be sure they are consistent with local test policies.
Reference information: Scheduling test activities.
Establish a fallback strategy.
Reference information: Coexistence and fallback.
Prepare for future installations.
Specific tasks are separating data from software, placing data sets on specific volumes, choosing a naming convention for data sets, using indirect catalog entries, using parmlib concatenation, and making optimum use of DASD space.

Reference information: Preparing for future installations.