Operation planning

<< Prev   Next >>

Version 2.1

Using MES tools on the shop level

Production schedule ensures a resource-coordinated stage allocation by planning intervals. Each department is obliged to perform its stages by the deadline specified in the production schedule. For departments, it is important not only to meet deadlines but also achieve the best technological and financial indicator values. MES tools can help you to accomplish both of these tasks. Using the MES tools, you can create an optimal operation timetable for work centers.

MES – Manufacturing Execution System, which carries out operation planning and production dispatching. MES tools allow you to considerably enhance operation planning capabilities, support multicriteria optimization option when creating a timetable, ensure scenario modeling when planning on the shop level, and expand production dispatching and timetable analysis tools. The system is oriented for use in discrete production.

You can create an operation timetable for production departments (list Enterprise structure) for which in the Route sheet management method attribute the Operation planning value is selected.

To receive real-time information on progress within the created timetable, operation performance registration is required. In the specified attribute, you can specify one of the following methods of operation performance registration for the department:

  • Register variances – only operations performed with variances from the created production timetable are registered. Operations without variances are considered to be completed on time.
  • Register fact – performance start and end are to be registered for all timetable operations. Operations whose performance state is not registered are considered to be not completed on time.

It is complicated to get a prompt feedback on operation performance without integrating the information system with an automated technological process control system and without using equipment sensors. To reduce impact of untimely recording of actual operation performance data on timetable dispatching, the Standard time to register operation execution parameter is set for departments. The attribute defines the maximum time within which the information on timetable operation performance start is to be recorded. If the information is not entered within this time, the operation is considered to be out-of-date and is to be replanned.

When you create a timetable based on criteria that reduce costs of the timetable performance, use values of the following attributes:

  • Rate (work) – standard equipment unit cost per hour.
  • Rate (changeover) – standard work center changeover cost per hour.

A dimensionless value is used for specifying rate values. The main condition is comparability of rates set for different work centers.

When creating a timetable, in stage description, it is necessary to specify operations sheets, which define technological operations.

Operation planning ensures parallel load of work centers.

Production process management in departments using operation planning methods is kept in Manufacturing – Shop management – Dispatching (MES). In this workplace, you can do the following:

  • Create and dispatch route sheets.
  • Create production timetable.
  • Assign (print) shift-day jobs.
  • Control production schedule and timetable deadlines.
  • Register product release.
  • Register employee output.

Before creating a timetable, split stages to be performed into production batches, each of which is presented by a separate route sheet (batch size is defined automatically by stage performance settings). To create route sheets by the selected date, click Generate route sheets. When being created, the route sheet is assigned the Created status. Route sheet parameters can be edited manually.

Operation time is specified in the Route sheet documents, on the Route tab:

  • Time per piece – operation time for one product unit/batch.
  • Setup time – total setup time for the production batch.
  • Time total:
    • For work centers without parallel load capability it is calculated using formula:

Time per piece * Product unit/batch quantity + Setup up time

  • For work centers being loaded on a parallel basis it is calculated using formula:

Time per piece + Setup up time.

To create and record operation timetable, click Generate timetable. The Operation planning dialog box appears.

Click Calculate and specify calculation parameters:

In the Planning timepoint parameter, set a date and a time starting from which the timetable will be calculated/recalculated. When you create the timetable, this parameter is used together with the Standard time to register operation execution attribute (the attribute value is inherited from the matching production department parameter). The combination of the specified parameters defines operations to be replanned.

If you select the Current time value, a new timetable is created for the following operations:

  • Operation 1 – all operations that should have started but did not start until the time delayed from the current time (according to the current application time) by the value of standard time to register operation execution.
  • Operation 2 – operations whose start time is later than the current replanning start time.
  • Operation 3 – operations not recognized as overdue at the replanning moment are not to be replanned (for example, if standard time to register operation execution is not expired for these operations).

If you select the Custom date value, a new timetable is created for the following operations:

  • Operation 1 – all operations that should have started but did not start until the time delayed from the current time (according to the current application time) by the value of standard time to register operation execution.
  • Operation 2 – operations whose start time is later than the specified custom time for timetable replanning.
  • Operation 3 – operations not recognized as overdue at the replanning moment are not to be replanned (for example, if standard time to register operation execution is not expired for these operations).
  • Operation 4 – operations whose start time is included in the interval from the current date to the selected replanning date (the Custom date attribute value) are not to be replanned.

In the Planning horizon field, specify a time period for which the timetable will be created. The period starts from the date selected in the Planning timepoint attribute.

Timetable generation rules are defined by the combination of planning model, operation planning scenario, and a flag of using equipment availability reserves. Unified sets of rules are presented in list Manufacturing – Settings and catalogs – Shop management – Operation planning models. The selected set of rules is specified in the Planning models field.

Operation planning models

Operation planning model options define the following:

  • Optimization criteria used when creating the timetable. They are expressed by the weighted value selected between two boundary options (target minimums):
    • Minimize execution time – key requirements are strict compliance with timetable deadlines and maximum high-performance equipment load. In this option, technological production factors are dominant.
    • Minimize timetable cost – calculated based on standard work time and changeover costs of specific work centers (equipment units). In this option, financial production factors are dominant.
  • Equipment Load method – shows usage option of replaceable equipment units (work centers within one work center kind):
    • Maximize load of equipment unit – operations within one work center kind are placed in a specific work center so long as it is available. If you use this option, the work center load might be uneven and downtime might happen regularly for some equipment. This option allows you to minimize demand for human resources and is especially useful if they are to be promptly reallocated.
    • Load equipment evenly – when generating the timetable, operations are allocated to work centers sequentially. This option allows you to equalize equipment unit output, but there is a high risk of downtime in all work centers.

Operation planning scenarios

To use scenario modeling for generating the operation timetable, open list Manufacturing – Settings and catalogs – Shop management – Operation planning scenarios. Each list item describes possible limits of changing production department parameters. The specified settings will be used for timetable planning. You can model the following situations:

  • Change of work centers. Possible options (the Work centers tab):
    • Expand equipment fleet – add an arbitrary quantity of work centers identical to the specified equipment.
    • Reduce equipment fleet – exclude the selected work centers from timetable calculation.
  • Work schedule management – assign the selected work schedule to a work center, work center kind, or department (the Work schedules tab).

Generating a timetable

Operation planning specifics:

  • Start and end time is calculated for each technological operation from the route sheet.
  • Maximum number of technological process parameters is considered.

The following data is used for generating the timetable:

  • Availability of main and additional work centers (including the ones being repaired):
    • Main work center kind – replaceable equipment group set to perform a specific technological operation (the Work center kind field on the Operations tab of the operations sheet).
    • Additional work centers are specified in technological operation parameters (on the Additional work centers tab, work center kinds or specific work centers are selected). Their load is planned together with the main work center. Additional work centers are such resource kinds as industrial equipment and worker teams.
  • Setup options and duration:
    • The setup option is specified in the technological operation parameters, in the Setup option field. The values are selected from the Setup options list, which is available on the navigation panel of the work center kind form.
    • Duration of the specific setup option is used.
  • Interoperation transfer parameters.
  • Availability reserves of work center kinds – you can configure equipment availability reserves in planning model rules (the Use reserve check box).
  • Condition of continuous technological operation placement – the Continuous attribute is set for technological operations. This attribute shows if the operation can be interrupted by unavailability intervals.
  • Work time factors of work centers.
  • Operation planning model settings.
  • Operation planning scenario settings.

To solve optimization tasks, greedy algorithms are used for timetable generation. A greedy algorithm makes optimal choices for solving the task at each stage until the global solution is found. At each stage, the choice is:

  • Acceptable – it matches the planning task conditions and limits.
  • Locally optimal – it shows the best solution among all options available at the stage.
  • Final – once made, the choice cannot be changed further.

The specifics below clarify the method name: the method includes a greedy choice of the best available alternative at each stage expecting that the sequence of locally optimal choices leads to a global optimal solution of the whole task.

Operation queue generation rules – sequential usage of methods:

  • By route sheet start date (ascending) – this rule shows the best results when planning operations having a high overlapping level. If required, changeover quantity is to be minimized.
  • By descending operation duration (first large operations, then the small ones) – this rule shows the best results if it is necessary to plan a large number of operations with different duration by having a small number of changeovers (or without them).

Work center queue generation rules:

  • Selection by planning model criteria – according to the specified ratio in the value range Minimize release date – Minimize timetable cost based on weighted values in planning model.
  • Ensure the minimum changeover time – this rule shows the best results if there is a great need for changeovers and work center load is high.

The generated timetable is displayed in the Operation planning workplace. You can configure how detailed the information is to be displayed. The following options are available: Day, Week, and Month.

On the operation timetable chart, time intervals with parallel work center load are highlighted. You can get an explanation for such load up to route sheets.

To analyze the generated timetable, use report Manufacturing – Manufacturing reports – Shop management – Operation timetable chart.

Operation performance marks

Within the timetable, each technological operation that was started or completed is to be marked as started or completed. To mark route sheet operations as started or completed, use workplace Manufacturing – Shop management – Operation performance:

You can mark operations directly from the list, without having to open route sheets for editing.

Registering operations with parallel load

To register parallel load (edit operation performance status), in workplace Manufacturing – Shop management – Operation performance, open an additional form of operation bulk selection. The form opens if the following conditions are met:

  • One line is selected in the list.
  • The work center supports synchronous parallel load.
  • Two or more operations are placed within the selected time interval.

In the Operation performance workplace, operations of route sheets with the For completion status are available for dispatching.

The Active status is not available for route sheets related to departments using operation management methods.

Route sheet statuses are set only manually. Change of the operation performance status does not affect the route sheet status.

If the Completed status is assigned to the route sheet, all operations within this document automatically get the Completed status.

General scheme of using route sheet statuses in operation management:

Route sheet dispatching

In the Dispatching (MES) workplace, you can see the current status of route sheets whose operations are included in operation timetable. The application controls what is required to do for these route sheets:

  •  – Include a route sheet in timetable
  •  – Register previous stage completion
  •  – Register employee output
  •  – Register product release or work fulfillment

The control results are displayed in the There are errors/warnings in the route sheet column. You can filter route sheets by the following variances from the generated timetable:

  • Production schedule is delayed.
  • Route sheet start has expired.
  • Route sheet completion time has expired.
  • Operation start date is overdue.
  • Operation completion time has expired.

If you regularly control timetable performance, you can identify that replanning is required in a timely manner. A timetable is replanned in accordance with the usual procedure in the Operation planning workplace.

Version 2.2

The functionality is available only for Production management, version 2.2 (if Master data and settings – Master data and sections – Manufacturing – Manufacturing – Production management, version 2.2 is selected).

Operation planning is done based on accepted for performance production stages with filled in operations sheets. After planning, production stage operations are arranged in sequence and linked to work centers.

Planning (generation of operation timetable) is available for production departments (the Enterprise structure list item) if in its profile, on the Production by orders tab, the Use operation planning check box is selected.

To generate an operation timetable for a specific department, use workplace Manufacturing – Shop management – Operation planning. Before generating an operation timetable, specify the following parameters:

  • Planning timepoint – date and time starting from which production operations will be placed.
  • Planning horizon – the interval with which production operations will be placed (starting from the planning timepoint).
  • Standard time to register operation execution – the maximum time within which the production operation start is to be registered. For example, an operation is planned for 8:00 AM, and the standard time is set to one hour. If there is no information on the operation start at 9:00 AM, the operation is to be replanned.
  • Department – shop, work area for which the timetable is generated.
  • Planning model – planning models and scenarios based on which the timetable is generated.

For each work center, specify a work time factor, as well as work and changeover rates, which are used when calculating operation performance cost for this work center using formula: Cost = Standard hours * Factor * Rate.

The planning model can include planning scenarios that allow you to configure the following:

  • Equipment fleet change:
    • Expand equipment fleet – for the work center kind, you can add a required quantity of additional equipment and specify its substitutes.
    • Reduce equipment fleet – you can specify certain work centers to be excluded from the planning (for example, due to repair).
  • Work schedule change:
    • For department – work schedule will be changed for all work centers of this department.
    • For work center kind – work schedule will be changed for all work centers of this kind.
    • For a specific work center – work schedule will be changed only for the specified work center.

To dispatch and control operation performance within operation planning, use workplace Manufacturing – Shop management – Perform operations (MES). In this workplace, you can manage operations in a flexible way (for example, create them in advance in relation to assignees and work centers – click Create), as well as control their actual fulfillment. Do the following:

  • Click Put into operation to create the Production operation document with the Active status and to specify an assignee for the operation.
  • Click Mark execution to create the Production operation document with the Completed status and to specify an assignee for the operation.

Once a production operation is completed, released products, actual material consumption, and labor costs are recorded. After that, this data is automatically imported to the production stage.

<< Prev   Next >>