Optimizing and Scheduling the Production Plan

You can optimize the selected production plan and publish it, to make the resulting schedule available for other systems or departments in your organization.

This task shows you how to:

Before you begin: Display your chart of choice to analyze the plan.
See Also
Plan Section

Configure the Optimization Process

You can verify, and modify if applicable, the Key Performance Indicators (KPIs) that the optimization process uses to come up with the best possible plan for your business goals. This configuration determines the optimization outcome and the resulting schedule.

  1. From the Plan section of the action bar, click Optimize the Production Plan.
  2. In the Production Plan Optimization window, the KPI Weights tab lists the KPIs available and their current weights for the optimization process. By default, the list is in descending order of weights, but you can click the KPI Weight column header to reverse that order.

    Important: The weight of a KPI determines the part it plays in the optimization process. Overall, the higher the value, the more important the KPI as an optimization objective. Yet, the calculated values of the KPIs do not necessarily compare. For example, some are straight numbers, like the number of work orders due in the scheduling horizon, while others are durations calculated in seconds, like the total waiting time. Now, the sum of the waiting times in seconds is likely a much larger figure than the number of unscheduled work orders. Therefore, using the same weight for both KPIs would give an inordinate importance to optimizing waiting times. So, when configuring the weights of the KPIs, be sure to take their value types into consideration. A weight of zero indicates that the optimization feature must ignore the KPI.

  3. You need to figure out which KPIs to optimize to come up with the best possible plan. For each KPI you need to edit, in KPI Weight, enter a numeric value that adequately reflects the position of that KPI in your optimization objectives, relative to the other KPIs. The value must be a positive integer number. To disable a KPI, enter 0.

    • Number of work orders that are due in the scheduling horizon but not scheduled: An operation is "due" in the scheduling horizon when its target end date falls within the scheduling horizon. A work order including such operations is also due in the scheduling horizon. With this KPI, the optimization process seeks to minimize the number of work orders including operations that are due but not scheduled. The default weight is 1000, because typically, you want to schedule all the operations that are due, even if that means some are late or downgrade other KPIs, for example.
    • Delivery performance: With this KPI, the optimization process seeks to maximize the percentage of work orders that are on time, relative to the total number of work orders in the plan. The higher the delivery performance, the better the customer service ratio. Typically, a good (green) value is above 80%. An average (yellow) value can range from +50% to 80% inclusive. An unsatisfactory (red) value is less than or equal to 50%.
    • Total lateness: With this KPI, the optimization process seeks to minimize the lateness of the WOs in the plan—that is, the time gap between the target end dates and the actual end dates. At the end of the optimization run, the value of the KPI is the sum of these time gaps in the plan.
    • Number of maximum delay violations: With this KPI, the optimization process seeks to minimize the number of operations that do not meet their maximum delay synchronization constraints with other operations. The default value, 25, is comparatively high, because typically, you want the resulting schedule to comply with these synchronization constraints.
    • Total duration of the maximum delay violations: With this KPI, for operations that do not comply with their maximum delay synchronization constraints, the optimization process seeks to minimize the time gap with the constraint. At the end of the optimization run, the value of the KPI is the sum of the remaining time gaps in the plan.
    • Total waiting time: With this KPI, the optimization process seeks to minimize the lag time (idle time) between operations in the plan. At the end of the optimization run, the value of the KPI is the sum of the remaining lag times in the plan.
    • Total changeover time: With this KPI, the optimization process seeks to minimize the tool changeover times between operations on resources in the plan. At the end of the optimization run, the value of the KPI is the sum of the existing changeover times in the plan.

The changes you bring to the configuration of the KPIs apply when you next optimize the production plan from the Optimization tab in this window. Conversely, the app does not save your changes if you close the window without running the optimization feature.

Note: The app displays only the KPIs that are active in the plan—that is, the KPIs whose weight is ˃ 0. Each production plan can have its own configuration of KPIs.

Run the Optimization and Scheduling Feature

You can optimize the production plan at any time, typically to include new work orders into the schedule and make sure that the resulting plan meets its business goals.

  1. (Optional) From the Plan section of the action bar, you can click Work Orders List to see if there are any unscheduled works orders. For more information, see List of Work Orders.
  2. From the Plan section of the action bar, click Optimize the Production Plan.
  3. In the Production Plan Optimization window, the Optimization tab shows the current status of the plan optimization, including:

    • The KPIs you are using to optimize the plan, each with its current value and its weight in the optimization process. They appear in descending order of weight—that is, from the most important KPI to the least important. The border color of a KPI indicates how the current value compares with your business goals for that KPI: green if performance is satisfactory, yellow if it is average, red if it is poor. For KPIs that do not have performance thresholds, such as those returning a number of hours, the border is gray.
    • The optimization curve, which shows how the latest optimization run progressed to reach its current results.

  4. To run the optimization feature and schedule the plan, click Start.

    Note: When the plan has concurrent users and one of them is running the optimization feature, the app notifies the other users that the feature is momentarily unavailable for them. Still, they can open the Production Plan Optimization window to see the progress of the KPI values. Similarly, no user can edit the configuration of the plan KPIs when the plan optimization is under way. When the optimization run stops, a message prompts these users to refresh the data in their widget. They can then use the optimization feature again.

  5. While the feature is running, the curve on the graph shows the optimization progress. Because the process seeks to minimize, and possibly eliminate, discrepancies with the business goals, the curve goes downward as the results get closer to the optimum.

    Note: The purpose of the curve is to highlight the trend of the optimization run, so that you can see at a glance how the overall result is improving. As for the Total KPI values on the graph, they may be nonsignificant, when they represent the progress of several weighted KPIs that have distinct calculation units.

  6. When the optimization run is complete—or when you stop it because the total score no longer changes—, the window shows the runtime duration and the new values of the KPIs. You can then click Close.

The chart you have selected shows the new plan as it results from the optimization and scheduling process. On analyzing the plan:

If applicable, you can also fine-tune the plan by moving individual operations to a different date or to a different resource. For more information, see Move an Operation in the Plan. When the plan is satisfactory, you can publish it.

Schedule Selected Operations

You can select an unscheduled operation and move it to the Resource Gantt Chart to schedule it. This is a convenient option to quickly update the plan without running the optimization feature.

  1. In the widget, display the Resource Gantt Chart, with the Unscheduled Operations list as the secondary view.
    The list displays any unscheduled operations in the production plan. Typical reasons why there may be unscheduled operations are as follows:
    • The production plan has received new work orders since you last scheduled it.
    • The production plan includes operations whose target end dates are later than the end date of the scheduling horizon, and that the optimization feature has not processed.
    • The production plan includes operations that a planner has unscheduled. See Unschedule Selected Operations.
    • You stopped the last optimization run before completion.
    • The weight of the KPI Number of work orders that are due in the scheduling horizon but not scheduled is comparatively too low. For the optimization feature, therefore, not scheduling some operations may be the solution with the least negative impact on the overall KPI results.
  2. In the Unscheduled Operations view, locate the row of the operation to schedule. This view offers all the standard features of a data grid. Therefore, you can filter and sort its content, for example, and choose the columns to display. For details, you can refer to the generic topic on configuring a data grid view for a dashboard app.
  3. Drag the operation row from the list to the Resource Gantt chart.
    The Gantt chart highlights the resources you can use for that operation, and dims all the other resources. Symbols in the vertical scroll bar identify the positions where you can find valid resources for the operation. This is convenient when some of the resources that you can use are not readily visible on the graph.
  4. In the Resource Gantt chart, drop the operation at the intended date on the resource you want to use. If this is an invalid start date because of a planning constraint, depending on the reason, the app cancels the action or uses the closest possible start date.

Provided the action is valid, the operation no longer appears in the Unscheduled Operations list, and the plan adjusts accordingly. Namely:

  • The app updates the sequence of operations on the resource where the new operation is now taking place. It recalculates the start and end dates of all the operations concerned, including the operations that are on other resources, but that have links with the sequence of operations you have modified.
  • The app recalculates the values of the KPIs. You can therefore verify the impact of the modified schedule on the overall quality of the plan.
  • The app updates also the workload of the resource concerned in the workload charts. For more information, see Monitoring the Workload of Resources.

Note: If the app cannot schedule the operation as requested, it displays a message and cancels the action. Depending on the reason for cancellation, you may try again. For example, if you dropped the operation on a resource that it cannot use, try scheduling it on one of its capable resources. Similarly, if you dropped the operation before an operation that is in progress already, try inserting it at another position in the resource's sequence of operations instead.

If applicable, repeat these steps to schedule other operations from the Unscheduled Operations list. Keep in mind that:

  • Adding many operations manually to the schedule can downgrade the optimization of the plan. If the list includes many operations that you need to schedule, consider running the optimization feature instead.
  • When you publish the plan, you save your changes. Yet, the optimization feature does not regard these changes as planning constraints. Typically, next time you run the optimization feature, it can reschedule the operations you have added to the plan on different resources and at different times.

Unschedule Selected Operations

You can remove an operation from the Resource Gantt Chart to unschedule it. Typically, this can be useful for simulation purposes, when you are analyzing the plan.

  1. In the widget, display the Resource Gantt Chart. Optionally, you can display also the Unscheduled Operations list as the secondary view.
  2. In the chart, locate the operation to unschedule.
  3. Right-click the operation and select Unschedule Operation.

The selected operation no longer appears on the resource. The app updates the resource sequence of operations accordingly, and recalculates the dates of all the operations concerned. If the Unscheduled Operations list is available as the secondary view or if you choose to display it now, you can see it includes the newly unscheduled operation.

Note: You can reschedule that operation at any time by moving it from the Unscheduled Operations list back to the Resource Gantt Chart or by rescheduling the plan. For more information, see the sections above.

Publish the Production Plan

You can publish the plan at any time, to save the schedule resulting from the optimization process and from any changes you and concurrent users have made to the plan.

  1. (Preliminary) If a message indicates that you are not viewing the latest planning data, you may want to select Refresh from the widget menu to update your view. You can then analyze the changes before you proceed. In fact, publishing the plan saves also the changes by other users. Therefore, it is usually best to make sure that you agree with those changes before you publish the plan.
  2. From the Plan section of the action bar, click Publish the Production Plan.
  3. A message confirms saving the planning data.

This data replaces the existing published data. At any single time, there is only one published ("official") version of the production plan. The data of the published production plan is the reference data for use by other apps.

Note: Users with viewing rights on a production plan can open only the published production plan. Conversely, users with authoring rights always open the "work in progress" production plan, which they can optimize, edit and fine-tune before they publish it.