Analysis and Adjustment Using the Gantt Chart

Review schedule analytics and use the Gantt Chart to review detailed aspects of your schedule using various filtering and highlighting features, and to perform manual schedule adjustments.

Analyze

• Before working with the Gantt Chart, you can review these analytics:

  • Late Work Orders: Number of work orders and planned orders scheduled for completion after their need-by dates.

  • Changeover Time: Sum of all changeover time durations.

  • Labor Utilization: Percentage of labor resource usage

  • Equipment Utilization: Percentage of equipment resource usage.

• Here are few things you need to know about color shades on the Gantt chart:
  • On work center resources that are setup with default units greater than one, the work order operations cannot be seen individually on the Gantt chart. In such cases, the resource usage is indicated via different colors. The darker shades of the color are used to denote heavier usage of resources.
  • Darker shade of the color used for work orders is used for planned orders from Oracle Supply Planning in the Gantt chart.

• In the Gantt chart toolbar, select a resource group. Use the Resource Group list to specify whether to review data for all resources or for a group of resources for schedule analysis.

  Note: When the Default Units Available value for a work center resource is more than 1, you can review resource levels using colors in the Gantt chart. Individual operations aren't displayed.

• Identify late work orders, using the Highlight Late action.

• Identify firm work orders, using the Highlight Firm action.

• Identify supplies and demands, using the Show Supplies action and the Show Demand action.
  • The Supplies row in the Gantt chart displays the purchase orders and inbound transfer orders.
  • The Demands row in the Gantt chart displays the sales orders and outbound transfer orders.
  • View downstream and upstream pegging links for the supplies and demands.

• Identify specific work orders or items. Use the Filter By and Filter Value fields to identify specific work orders or work orders that produce specific items. More information is displayed when you hover over an operation in the Gantt chart.

  Note: The Filter By values Asset and Type apply to Maintenance work orders only.

• Identify operations by attribute. Use the Highlight Attribute options to select an attribute in order to highlight all work orders or items defined with that attribute. For example, if your attribute is Pack Size, then all operations with the Pack Size attribute will be highlighted, and those with the same pack size value will be displayed in the same color that was assigned to that size.

• Identify task dependencies. Select any operation, supply, or demand to view its pegged upstream and downstream operations, supplies, or demands. Solid lines indicate successive operations within the same work order routing. Dashed lines indicate inventory relationships between supplies and operations, between operations belonging to different work orders, operations and demands, or supplies and demands. Dashed lines can indicate these scenarios:

  • A producing work order feeding one or more downstream consuming work orders or demands.
  • A consuming work order receiving components from one or more upstream work orders or supplies.
  • A supply feeding one ore more demands.
  • A demand receiving components from multiple supplies.

  Straight vertical lines indicate highly synchronized production, and diagonal lines indicate less synchronized production. These lines are also called pegging links and are visible only when the Show Pegging Links button is selected.

  Note: The Show Pegging Link button should be selected to view the pegging links for work orders.

• Identify and review idle times, changeovers, and downtime events.

• Identify the start and end of schedule horizon. The first solid vertical line represents the start of the schedule horizon; the second solid vertical line represents the end of the schedule horizon.

• Identify the end of the fixed time fence and end of the resource constraint horizon. The first dashed vertical line represents the end of the fixed time fence; the second dashed vertical line represents the end of the resource constraint horizon.

• If the Display of Resource Units in Gantt Chart check box is selected on the Resource Parameters page, you can view the resource usage levels of that particular resource, as well as individual work order operations that are scheduled on that resource. If the check box isn't selected on the Resource Parameters page, then you can view only the aggregate resource usage levels.
• Identify downtime of resources. Grey areas in the background of a schedule indicate downtime for that specific resource.

Adjust

You can change resource assignments and manage downtime events in the Gantt Chart.

• Change the resource or start time for an operation.

  1. Move an operation from a resource to an alternate resource by dragging and dropping it, or move it backward or forward in time on the same resource. You can also select a sequence of operations to drag and drop.

     • For resource offloading to work within Production Scheduling, the resource sequence number of the work order operation must match the resource sequence number of the work definition operation in the Supply Chain Execution work area.
     • If you cannot offload an operation to an alternate resource, then verify the presence of alternate resources in the respective work definition operation-resource sequence in Supply Chain Execution, Work Definition, and that the work order is not firm.
     • Phantom components with resource alternates in their work definition may not be offloaded by the system. This may be because the phantom explosion process in Work Execution during work order creation can introduce inconsistencies in resource sequence numbers.
     • Alternate resources and operation attributes exist on the work definition but not on the work order within the SCM Execution. To ensure they are included in a production schedule, the work definition should be setup such that the phantom items are consumed by a separate (upstream) operation-resource sequence with Scheduled flag set to No.

  2. Specify the operation start time and click Save. If you selected multiple operations, specify the new start time of the first operation in the sequence.

  3. Click Repair to ensure that the schedule accommodates the adjustment. Here are some things to consider when you do a repair after a drag and drop operation:

     • Dropped operations are scheduled one after the other without any time gap.
     • For constrained resources with default units available set to one, any overlaps among the moved operations will be resolved and changeovers will be inserted as per the defined changeover rules.
     • If operations were offloaded, then only the target resource will be rescheduled and not the original resource.

• Manage downtime events and availability. Click the Edit Calendar Events button in the toolbar to enable the edit calendar events mode. You can add or remove downtime, or add availability only in this mode. After making the changes, click the Edit Calendar Events button in the Gantt toolbar again to de-activate the edit calendar events mode.

  • Add a downtime event.

    1. Right-click on the schedule.

    2. Click Add Downtime.

    3. Enter the resource or resource group, start date, start time, end date and end time.

    4. To modify downtime over a specific period of the schedule horizon, select Recurrence check box. You can define recurrence only if the events have duration of up to 24 hours.

       1. Enter the Start On date and the End By date. The period should be within the schedule horizon.
       2. Select the weekdays for which the downtime has to be applied.
    5. Click OK
  • Remove downtime event
    1. Right-click on the schedule.
    2. Click Remove Downtime
  • Add availability
    1. Right-click on the schedule.

    2. Click Add Availability

    3. Enter the resource or resource group, start date, start time, end date and end time.

    4. To modify downtime over a specific period of the schedule horizon, select Recurrence check box. You can define recurrence only if the events have duration of up to 24 hours.

       1. Enter the Start On date and the End By date. The period should be within the schedule horizon.
       2. Select the weekdays for which the availability has to be added.
    5. Click OK
    6. Click Solve to ensure that the schedule accommodates the new resource availability and new downtime.

Note: The solve process discards manual adjustments to work order operations, including those saved using the Repair action, and calculates a new schedule.

Note: In order to ensure predictable repair solve results, avoid performing both drag & drop actions in the Gantt chart and resequencing actions in the Dispatch List involving the same work order operations. Repair the schedule after Dispatch List resequencing and also after Gantt chart drag & drop actions.