What is CPExpert?

CPExpert is a software program that runs on your IBM mainframe, analyzing data in your MXG®, MICS®, or SAS-ITRM® performance data base. CPExpert runs as a normal batch job, and it:


  • Reads information from your system to detect performance problems. 

  • Consolidates and analyzes data from your system (the data normally is contained in a performance data base) to identify the causes of performance problems. 

  • Produces narrative reports to explain the results from its analysis, and to suggest changes to improve performance.


CPExpert is implemented in SASŪ, and is composed of hundreds of expert system rules, analysis modules, and queuing models. CPExpert has different components to analyze different aspects of system performance.  Breaking the product into "components" allows you to license only those analysis modules that meet your performance analysis needs.

When CPExpert was introduced in 1991, the product  provided analysis of IBM performance problems that existed prior to Goal Mode.  The analysis provided with CPExpert have changed since the product was initially released and the components that apply only to MVS Compatibility Mode are no longer marketed.  While these "legacy" components are not marketed, they are described at the end of this page to give you an appreciation of CPExpert's history.   

The following five components now are provided with CPExpert:  

  • The DASD Component was introduced in 1991.  The DASD Component identifies DASD volumes with the most significant performance problems and suggests ways to correct the problems.  The DASD Component has been enhanced over the years, to include other DASD analysis (such as cache controller analysis,  VSAM analysis to automate most of the analysis contained in IBM's VSAM Demystified Redbook, etc.).


  • The CICS Component was introduced in 1992, supporting early versions of CICS.  The CICS Component now analyzes standard CICS interval statistics, applying most of the analysis described in IBM's CICS Performance Guides. All versions of CICS are supported (including CICS/TS for z/OS Release 5.3).  The CICS Component analyzes standard SMF Type 110 records (subtype 2,3,4, and 5 interval statistics records).  MXG is required to execute the CICS Component, because MICS does not provide the detailed CICS interval statistics (only SMF Type 110 subtype 1 accounting records are processed by Mics).


  • The WLM Component was introduced in 1995.  The WLM Component initially was designed to process MVS Goal Mode data: detecting problems with the Workload Manager Service Definition, evaluating overall MVS performance problems, determining when service classes miss performance goals, analyzing data to determine why the goals were missed, and suggesting alternatives to improve system performance. Since the WLM Component was introduced, additional analysis has been added to this component; the WLM Component now analyzes problems with coupling facility/XCF, paging subsystem, system logger, zSeries Application Assist Processors (zAAP), and System z9 Integrated Information Processor (zIIP). With Release 15.1 (April 2005), the WLM Component was enhanced to analyze PR/SM performance problems. With Release 15.2 (October 2005), the WLM Component was enhanced to analyze Intelligent Resource Director (IRD) performance problems. Other areas analyed by the WLM Component include WLM-managed initiators, HiperDispatch, Resource Enqueue problems, and System Management Facilities (SMF) performance issues.  


  • The DB2 Component was introduced in 1999.  The DB2 Component processes DB2 interval statistics data to evaluate the performance of DB2 for OS/390 or DB2 UDB for z/OS. The DB2 Component automatically applies most of the DB2 analysis techniques documented in IBM's DB2 for OS/390 or DB2 UDB for z/OS Administration Guides, supplemented by techniques and guidance contained in IBM Redbooks, by papers presented at various technical conferences, and by IBM's suggestions in the DB2 DSNWMSGS macros.


  • The WebSphere MQ Component was introduced in 2004.  The WebSphere MQ Component identifies common performance problems with WebSphere MQ for z/OS, and suggesting alternatives to improve system performance. CPExpert analyzes the standard WebSphere MQ for z/OS data, as written to SMF Type 115 (and optionally Type 116 records). Please note that IBM renamed MQ Series as WebSphere MQ, with Version 5.2.



Each component includes an extensive user manual to provide a description of each potential problem, the likely impact of the finding, a discussion of the z/OS concepts relating to the potential problem, suggestions for improvements, and specific references where more detailed information can be obtained. The User Manuals consist of over 3,000 pages of documentation.

The CPExpert philosophy is to offer a low-cost product to help solve common performance problems in z/OS environments. One result of this approach is a tremendous amount of "leverage" since CPExpert users do not have to keep "reinventing the wheel" - solutions to common problems are made available through CPExpert.

Periodic documentation and software updates are provided as a part of the license fee. Since initial delivery in April 1991, CPExpert has been updated to support each new release of MVS or z/OS within 30 days of General Availability date of the new release of the IBM software.


Legacy Components.  The "legacy" components of CPExpert are no longer marketed, since the relevant analysis has been incorporated into the WLM Component.


  • The SRM Component was introduced in 1991.  This "legacy" component analyzes SYS1.PARMLIB members to identify problems or potential problems with your IPS or OPT specifications, and to provide guidance to the other CPExpert components. The SRM Component is applicable only to Compatibility Mode.


  • The MVS Component was introduced in 1991.  This "legacy" component evaluates MVS performance problems in the major areas of MVS controls (multiprogramming levels, system paging, preventable swaps, logical swapping, expanded storage, and cross system coupling facility). The MVS Component is applicable only to Compatibility Mode.


  • The TSO Component was introduced in 1991.  This "legacy" component identifies periods when TSO response is unacceptable, "decomposes" the response time, and suggests ways to improve TSO performance. The TSO Component is applicable only to Compatibility Mode.


Want more information about CPExpert components?  View the CPExpert marketing presentation foils, or click on one of the below components.




WebSphere MQ





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Last updated by Don Deese on 5/16/16.