Analyzing the impact of changes on your environment
How to apply changes to your plan and see the related impact displayed in a Gantt chart.
The What-if Analysis visualizes the current plan in real time, displaying the current status of jobs and job streams, the planned start and end times, deadline, and the risk level associated to each job or job stream. The analysis is launched from any job or job stream in a distributed environment, or from any critical job or job that is part of a critical network in a z/OS environment. This feature is supported on version 9.3 engines or later. The current plan is visually represented in a Gantt chart. A Gantt chart is a time and activity bar chart that is used for planning and controlling projects or programs that have a distinct beginning or end. In a Gantt chart, each main activity that is involved in the completion of the overall project or program is represented by a horizontal bar. The ends of the bar represent the start and end of the activity. In IBM® Workload Scheduler, each activity represents a job or job stream.
Use the What-if Analysis to simulate and evaluate the impact of changes on the current plan. For example, if you know that a required file will be made available later than expected, you can evaluate the effects on the whole plan of the delay in the delivery of the file and see in detail which jobs and job streams risk missing their deadlines. For example, if you know that a specific workstation is scheduled to undergo a programmed maintenance operation, you can simulate the impact of the missing workstation on the overall plan.
Drag and drop each job or job stream along the horizontal time axis to see how this changes the job or job stream status with respect to its planned deadline. For example, if you move a job too close to its planned deadline, its status changes to indicate a potential problem. When you move a job or job stream, its dependencies are maintained and automatically recalculated. You can also add and remove successors and predecessors for each job or job stream.
If you need to enlarge the scope of your analysis, you can add more job streams and jobs to the Gantt view using the Show Jobs and Show Job Streams (distributed only) buttons. This operation performs a search on the current plan and adds the selected jobs or job streams with the related predecessors and successors.
You can also highlight the critical path for a selected job or job stream along with its successors and predecessors. Modify the job duration, start time, and end time, add or delete successors and predecessors and see how this affects the whole critical path.
Under More Actions tab of the context menu you can find the Workstation Unavailability Intervals page where you can select intervals of time when the workstation will be unavailable. Use Simulate Job Stream Submit (distributed only) to simulate the impact of submitting a job stream. The predecessors and successors will not be matched automatically.
If you want to view the current plan again, click What-if Analysis to the current plan status.
to revert theRunning the What-if Analysis before carrying out the actual plan shows your predicted results at a glance, and, by seeing the results beforehand, you can plan for any potential problems before you start.
Any changes that you make in What-if Analysis are applied for simulation purposes until you use the option Apply changes to the actual plan with exception to a z/OS environment where changes are made for simulation purposes only.
You can disable the What-if Analysis in your environment by setting the optman
enWhatIf | wi
global option to no (default value is yes ). If you
change this global option value, run "JnextPlan" to make the change effective. For additional
information about optman global options , see Setting global options.
The enWhatIf | wi
global
option interacts with the enWorkloadServiceAssurance | wa
global option, which
enables or disables privileged processing of mission-critical jobs and their predecessors. For
details about the interaction between the What-if Analysis and the
workload service assurance, see Disable the What-if Analysis.
If you want to extend the What-if Analysis to plans other than the current plan, consider that the maximum number of plans that you can analyze simultaneously is 5.
If you want to use the What-if Analysis on the backup master domain manager, ensure that on the backup master you have the same user definition as on the master domain manager.
If the administrator has enforced the related policy, when you apply the changes to the actual plan, a panel is displayed, where you enter the reason why the change was implemented, the ticket number, if any, and the category of the change. For more information about the justification policy, see Keeping track of changes to scheduling objects.