As part of the Lead Time package, we include the following tools:

Cache Predictor

A cache hit Predictor has been added to the Lead Time Tools menu. The goal is to estimate the cache hit ratios for a given cache size using the cache hit ratios for the current cache size. This Predictor is simple to use and very fast. It can be particularly useful when using Lead Time to represent Open Systems environments since controller cache statistics are generally not available from standard system instrumentation in Open Systems. Note that cache hit prediction is not a well established and validated technique. More reliable results can be expected from I/O traces and cache simulation.


A companion mainframe data extractor. Together with model generating facilities of Lead Time, Xtract allows near-automatic building of a Lead Time model corresponding to the observed workload of a selected set of devices in the user’s system.

Currently, we support:

  • Standard RMF (MVS/XA, MVS/ESA) or compatible data
  • Cache RMF, device and dataset level information created by Computer Associates ASTEX™ system monitor
  • GTF trace data
  • CSIM fromAmdahl Corporation
  • VM Monitor data (XA/ESA)
Based on user’s specifications, Xtract preprocesses monitor data for the selected devices, and produces a data set that contains the information necessary for Lead Time to build the corresponding model. After transfer to the Personal Computer, the data prepared by Xtract is used to build the model and to initialize quantities not directly provided by the system monitor. The net result is a greatly simplified model building and calibration process.The JCL to run Xtract can be produced by our Windows-based utility Xtgen freeing you from the need to learn Xtract control language. Xtract can be run under MVS or VM.
OSX™A companion tool to process files exported from HDS GRAPHTrack utility. Together with model generating facilities of Lead Time, OSX assists in building Lead Time models in Open System environments with supported HDS controllers. Currently, we support Export files created by versions 3 and 4 of GRAPHTrack.SANModel™ 

A companion tool to model selected in-line Storage Area Network configurations. The tool is fully integrated with Lead Time, and can be run from within Lead Time or stand alone, invoking the Lead Time modeling engine as necessary.


When a GTF trace is used as a source of monitor information, GTFSIM™, a special facility on the Personal Computer side allows to run simulations of various environments to accurately assess the effect of varying cache and NVS sizes, as well as of specific treatment of Define Extent flags as used by System Managed Storage.