SapPreventive Maintenance

Editor's Notes

1. SaskPower maintains more than 93,000 miles of power lines Our available capacity is approximately 3,100 megawatts (MW). This includes 2,880 MW of supply generated by our own facilities - 3 coal-fired stations, seven hydro stations four natural gas stations - Our 25-year power purchase agreement with the Meridian cogeneration facility at Lloydminster Service over 430,000 customers in a population of 1,000,000 Service area of over 200,000 square miles of a total area of 250,000 square miles or roughly the size of Texas Our 2,300 employees work in three business units (Power Production, Transmission and Distribution, and Customer Services), We are using FI, CO, PM, PS, IM, SD, MM Full HR with Payroll
2. These are the standard tasks maintenance workers need to perform to maintain a piece of equipment. Disconnect electrical supply Disconnect instrumentation Replace equipment Task lists are a very important part of preventive maintenance. These are the operations inserted into the automatically generated orders Task lists with similar steps are combined into Task list groups Task List group Cranes Contains task lists for maintenance of various type of crane. At Sask Power we matched out Task list Group number to the catalog Profile number assigned for this type of equipment. Equipment and Functional Location task lists have internal number assignment General Task lists can have either internal or external; assignment Operation relationships may also be created in the task list.
3. Equipment task List always object based created for specific individual pieces of equipment Functional Location Task list also object related created for specific functional locations General Maintenance Task Lists no object reference General steps for maintenance of many pieces of equipment of similar nature (pump maintenance) At Sask Power we use mainly General Task Lists. All three types of task list may be used in routine and preventive maintenance.
4. Purpose To generate a call object automatically for a particular date (when used with deadline monitoring) Call Objects are Maintenance Notifications, Maintenance orders or service entry sheets Maintenance Notification designed for internal processing An order can be created from the notification if required. Maintenance Order designed for internal processing Can create a notification shell at time of creation o Notification can be created from the order at a later date, Service Entry Sheet designed for external processing Created with reference to a framework agreement Generates service entry sheets Available to service providers to enter the services provided.
5. Maintenance item Reference object Functional Location , Equipment Planning Data Planning Plant Planner Group Order Type or Notification type Maintenance Activity type Main Work center Business area Task List Details of task list group and counter number Task List Description Scheduling Data Arranged in 4 Tabs Maintenance Plan Cycle Maintenance Plan Scheduling Parameters Maintenance Plan Additional data Maintenance Plan Scheduled Calls
6. The reference object area contains information about the technical object being maintained.( Functional Location and or Equipment Note the icon beside the equipment number this indicates a document is linked to the object and can be viewed and printed from here. The planning data Contains the information as to what plant, planner group and main work center are to be populated on the call object. The call object is also indicated in this area . A priority may be assigned to the call object. The task determination can be used to have the system automatically generate tasks for a notification. This require some configuration of response profiles (Time interval within which a predefined task must be performed Relevant code defined for this task) and service profiles(The availability times defined in the service profile form the basis for the calculation of the start and finish dates defined at task level). These are in turn assigned to the notification type. Task list area Contains the information pertaining to the task list and allows the creation of a task list if one does not exist or the canceling of a task list assignment.
7. Contains Four main Tabs Listed earlier. The information on each tab will be explained in more detail in future slides dealing with the creation of a maintenance plan
8. Single Cycle Plans Simple to create Cycle can be any unit of measure in the system May be used with or without a task list Task List may be created directly in the plan Select The call object Type for your plan This is not editable after the plan is created The order type or notification type is selectable
9. The Short Text A description of the maintenance plan. This text copies to the Short text Description of the maintenance item. If no task list is assigned to the maintenance plan the system will copy this description into the operation text of the order created by a call. The cycle and cycle unit are the number and unit of measure for your cycle (1 week 1month 1year 50 tons etc.) Cycle text text description of the cycle The cycle offset is the time which the maintenance plan may be set to come due the first time. This is a mandatory entry if the first time due does not correspond to the cycle of the plan (Eg. This is a 2 year cycle the plan first time due 3 years.) The Counter is the system assigned number of the Measuring Point that will generate a call by the entry of a measurement document
10. Shift Factor Late or Early Confirmation If the plan is confirmed late this is the percentage the call date will be shifted. Shifts will only occur if the variance is outside the target range. Tolerance Late or Early Confirmation percentage of the cycle that can elapse before a shift of the start date will occur (cycle 30 days X Tolerance 10% = 3days late before shift is applied. Cycle Modification Factor Factor when multiplied by the cycle in the plan will generate custom call periods for individual plans . Extremely useful in adapting maintenance strategies to for custom periods. Factors greater than 1 increase the cycle factors less than 1 decease the cycle. Maximum value is 9.99 and minimum value is 0.01 Factory Calendar Specific calendars can be assigned here. The system will propose the default calendar for the plant in a single cycle plan. Call Horizon Determines when the call object( maintenance order etc.) should be generated for a maintenance call. This a percentage of the cycle ( 30 day cycle 90% call horizon. The call will occur at 27 days from the start of the cycle. Scheduling Period The length of time the system creates maintenance calls during Maintenance Plan scheduling. (1 week cycle 52 week period there will be one called object and 51 on hold objects. Requires Confirmation Checking this box caused the system to hold all future calls until the current call is confirmed ( call object completed TECO for Orders NOCO for notifications Start of Cycle Start date for the maintenance plan. Date can be set in the past.Can be completed now or user will be prompted when plan is saved to indicate a cycle start user may still opt to not input a cycle start until ready to schedule the plan
11. Sort Field Drop down list of entries set in configuration Allows searching an grouping of maintenance plans in a plant. Authorization Group Allows creation of security for processing of this object (Maintenance plans) Maintenance Plan Category Selected initially when plan is created (type of call object to be generated by the plan) Can not be changed after plan is saved initially.
12. Reference Object The technical object the plan has been created for May be a Functional location equipment or assembly. Any one or all three may be populated depending on where the object is in the structure. Planning Plant Defaults from the technical object. Maintenance data Order Type This is the individual types with in the call object (one of many order types or notification types) Main Work Center Defaults from the technical object maintenance Data. Priority Based on defaults for order type. Can be set here or manually after call object is created. Maintenance Planner Group Defaults from technical object. Do not confuse with capacity planner group assigned to the Work center. Maintenance Activity Type May be set here list is Maint Activity types valid for order type. Settlement Rule Pertains to orders only may be created here or later when the order is called Task List Single cycle plans may or may not have task list May be created or changed from the maintenance plan. When the maintenance plan is saved it is now ready for scheduling. Note the plan will not generate any calls until scheduled
13. The initial screen provides two options for initial scheduling of single cycle plans Start Manual Call Clicking either button will bring up a dialog box prompting you for a date Today’s date will default. If the start of cycle date was entered in the maintenance plan prior to saving this date will default as the start of cycle date in the dialog box. Accepting the date will populate the plan date with date for the first order. If this date is with in the call horizon the Date Type Status Field will read New start Save to call. (Saving the plan will generate a call object in this case an order) If the date is outside the call horizon the field will read New start Hold (the call of the object is on hold until the call horizon is reached. The order is generated by Deadline monitoring.) Special Scheduling Functions Release The system releases the call and creates a maintenance call object (for example, maintenance order) when you save. Fixed The system makes the field Planned date ready for input. The system fixes the call for the date entered. Skipped The system will ignore this call and no maintenance call object will be created for it.
14. Update Scheduling The system calculates the maintenance calls based on maintenance cycles and the scheduling parameters . It ensures that at least one scheduling record exists that has the status On hold. This should be done after releasing or fixing a call to ensure at least one call on hold. Scheduling Algorithm The algorithm provides an overview of the scheduling information that determined a particular maintenance call. The scheduling algorithm displays: Scheduling parameters Status Actual dates Planned dates Shift factor The actual and planned confirmation dates are displayed in the scheduling algorithm you can easily compare deviations between these dates Display Call Object This icon allows access to the call object Order Notification or Service Entry in display mode. Confirm This icon marks the call as completed (please be aware this has no effect on the call object it will not Technically complete an order, Complete a notification, or Verify a service entry.If these functions are carried out in the respective call object the type status field will show completed. These functions are available in all types of maintenance plans when in change mode.
15. To reschedule a plan that is running click the Restart button A Dialog box appears with choices as to the scheduled hold calls. Any Called objects will remain until completed. If the delete button is selected all on hold lines will be deleted and the new schedule will be the first line displayed after called lines. If the Skip Button is selected the on hold calls will be skipped but remain in the list for historical purposes. To undo scheduling exit the maintenance plan with out saving or use menu path Edit>Undo Scheduling
16. Definition A Maintenance strategy consists of several maintenance packages and represents the scheduling rule for preventive maintenance Types of Maintenance Strategies Time base maintenance plans are just as their name states after a period of time has elapsed maintenance is performed (every three months once per year weekly etc). The combination of packages creates a unique scheduling scheme for maintenance (maintenance tasks may be performed monthly, but at 3 month intervals additional tasks may need to be performed or a group of totally different tasks will be executed. Performance based strategies rely on the entry of measurement documents from counters to trigger maintenance. Creation and Change of Maintenance Strategies is Master data in 46C Recommend that the access to the transaction be very limited. Task Lists and Maintenance Strategies When a task list is assigned to a maintenance strategy, the assignment of packages to to the operations of the task list determine which operations appear in the call object (work order)at what time.
17. Name Descriptor used to identify the the maintenance strategy(PP indicates Power Production group we also use FL Fleet Services, IT for our Corporate Information and Technology, TD for our Transmission and Distribution Group. Description 40 character description of the Strategy Scheduling Indicator Several scheduling indicator are available for time based strategies Time uses elapsed time to trigger the next maintenance call based on the strategy unit ( Weekly unit maintenance is called every 7 days. From the current date.) Key Date uses elapsed time to trigger the next maintenance call based on the strategy unit. The call is made on a specific date (4th day of each month Factory Calendar uses elapsed time to trigger the next maintenance call based on the strategy unit the call is made only on a work day. ( Current date or next Workday no calls on non work days)
18. Some of the information here is the same as the information ion the scheduling parameters tab of the single cycle plan. Strategy Unit This is the unit of measure for the strategy may be days weeks months years etc. Call Horizon Determines when the call object( maintenance order etc.) should be generated for a maintenance call. This a percentage of the cycle ( 30 day cycle 90% call horizon. The call will occur at 27 days from the start of the cycle. Shift Factor Later or Earlier confirmation If the plan is confirmed late or early this is the percentage the call date will be shifted. Shifts will only occur if the variance is outside the target range. Tolerance Later or Earlier Confirmation percentage of the cycle that can elapse before a shift of the start date will occur (cycle 30 days X Tolerance 10% = 3days late before shift is applied Factory Calendar Specific Factory calendar determining work days for a plant The factory calendar that you specify in the maintenance strategy is copied as a default value to the strategy plan if the strategy plan has the scheduling indicator Time - key date or Time - factory calendar. Statistics Box Has a display of the number of packages assigned to the Stratagey Icon to generate a strategy where used list An example of the list is displayed on the next slide
19. This list is generated by clicking on the where used button in on the maintenance strategy details screen The list provides details about all maintenance plans using this Maintenance Strategy By clicking on the plan number and then clicking on the maintenance plan icon you are taken directly to the Maintenance plan in display mode.
20. Definition Maintenance packages define the frequency at which specific operations are executed. Packages are assigned to operations in the task list. Parameters Maintenance package number (sequential) Cycle Length and Unit time period for each package (week month year etc.) Description of the package Short Description This is the value that appears on the package sequence display Hierarchy If two maintenance packages are due at the same time the hierarchy determines which will be performed. The lower level hierarchy is not performed.(Pack 1 change oil 3000 miles Pack 2 hierarchy1 rotate tires 12000 miles, Pack 3 hierarchy 2 service transmission 48000 miles. At 3000 miles an oil change is called at 12000 miles an oil change is called as well as a tire rotation. At 48000 miles a transmission service is called the other two packages are omitted. If the package 3 had a hierarchy of one all three packages would be called Offset As in single cycle plans this determines the due date of a maintenance package. Preliminary/Follow up Buffer specified in days with reference to the planned date and sets the basic start and end dates for a maintenance order. Package Sequence Icon allows an overview display of the packager sequence based on the hierarchy assignments
21. The package sequence is accessed by clicking the Pack.Seq icon on the Maintenance Strategy detail screen The time line is displayed across the top the package numbers appear under appropriate month in this case. (package #2 - 3 Month appears under month 3, 9 and 15 while package #3 - 6 month appears under months 6 and 18
22. Task lists created for use in Preventive Maintenance Strategy plans require two things: The strategy must be assigned in the task list header, Maintenance packages are assigned to the operations in the task list. This defines the frequency in which the operations are executed.
23. The name and description perform the same function here as discussed earlier. Scheduling Indicator performance based Strategies will all have Activity as their scheduling indicator. Strategy Unit Will be one of the defined units in your system (Hrs. Liters gallons miles yards etc.) Call Horizon Talked about previously Typically will be set to 100% Triggers will be the through put of some type measured by a counter. Shift Factors Talked about previously again typically set to zero Performance based strategies are only used when equipment or functional location have measuring points with counters assigned. The trigger or call of a maintenance plan is determined by regular entry of measurement documents with readings from the counter.
24. You will note that all packages have individual hierarchies.as a result no operations from the task list that have a package assignment other than the current package will be called at any one time If the 100 hour package had a hierarchy of 5 the same as the 50 hour package then both would be called at the same time when 100 hours had elapsed on the counter. This is based on entries made from measurement documents for the this counter. The setup of the packages and associated hierarchy will provide a great deal of flexibility in determining what work will be done at each maintenance call
25. Maintenance plan number is assigned by the system when the plan is saved discussed earlier Maintenance Plan category is either Work Order, Notification, or Service entry. Discussed Earlier The strategy will be one of the strategies currently set in the system and can be either Time Based or Performance Based.
26. The short text description of the maintenance plan is a mandatory field Counter This is the internal number assigned to the measuring point whose counter will trigger the the call of the maintenance plan the measuring point is assigned to the technical object in the maintenance Item. Note the cycle data is still blank , this will be populated later when a task list is selected for the maintenance plan. The packages used in the task list are displayed as cycles in the maintenance plan only packages used are displayed.
27. When the equipment number was entered a large amount of the information in the Maintenance Item is populated The priority can be pre set here so the order will automatically have a priority or if left blank the priority can be assigned later when the order is scheduled. Note If in your system you have configured the order type to be released automatically this order will be released when created. Task List Selection Clicking the Binoculars icon takes you into the task list selection screen. Information from the maintenance item and the maintenance strategy default into the selection screen. This allows only the selection of task lists that are valid for this maintenance strategy. The equipment and functional location also default in so as to allow the selection of either equipment specific for functional location task lists as well as general task lists. The selection of a task list will populate the cycle area of the maintenance plan with the maintenance packages that are assigned to this task list as discussed earlier. You May also create the task list from the maintenance plan if no suitable task list exists
28. The maintenance cycle has defaulted due to the package assignment in the task list. The package assignments become the cycles in the maintenance plan When you save the maintenance plan a dialog box will pop up asking if you wish to specify an initial start counter reading. This should be as close to the reading after last maintenance was performed as possible. If you enter 1 as the reading here the plan will generate a call for each block of 30,000 operations. This is of course only if you have not specified requires confirmation.
29. When scheduling a performance based plan for the first time several options exist. Start a dialog box appears with a field populated with the current total counter reading appears. This is the reading the plan will start counting from to generate the next call. The reading should be the reading at the time the last maintenance was performed or the in service reading of the counter for new technical objects Manual Call a dialog box in the dialog box the user has the ability to call date. A second dialog box appears providing the opportunity to select which package you wish to call. When a manual call is made it is recorded on the manual calls tab. Start in Cycle Dialog box appears the user has the ability to set the start counter reading of the last maintenance(current reading is defaulted) The user then may select package of the last maintenance to set the start offset. The system flags the new start offset with a call symbol. Scheduling begins with the package(s) after the start offset The system calculates the next due packages based on the scheduling information in the maintenance plan. For performance-based maintenance plans, the system also considers the current counter readings and annual estimates to provide scheduled calls on hold. The Scheduled Calls tab contains the counter information including the expected counter reading for all calls and scheduled on hold cycles. This is the total counter reading for the object not the actual counter reading on the current counter.
30. When rescheduling a performance based Maintenance Plan two options exist. Restart A dialog box appears to select what to do with all on hold calls the standard option is to select delete or the user may select skip if you require a history to be maintained. After the selection is made a second dialog box appears to input the start counter reading. Note when rescheduling a maintenance plan outstanding calls (orders, notifications, or service entries are still active. The system will not automatically close these objects they must be dealt with in the normal manner. Start In Cycle A dialog box appears to select what to do with all on hold calls. After making a selection the functionality is the same as for Start in Cycle for new plans.
31. Maintenance plan number is assigned by the system when the plan is saved discussed earlier Maintenance Plan category is either Work Order, Notification, or Service entry. Discussed Earlier The strategy will be one of the strategies currently set in the system and can be either Time Based or Performance Based.
32. The short text description of the maintenance plan is a mandatory field Note the cycle data is still blank , this will be populated later when a task list is selected for the maintenance plan. The packages used in the task list are displayed as cycles in the maintenance plan only packages used are displayed.
33. When the equipment number was entered a large amount of the information in the Maintenance Item is populated The priority can be pre set here so the order will automatically have a priority or if left blank the priority can be assigned later when the order is scheduled. Note If in your system you have configured the order type to be released automatically this order will be released when created. Task List Selection Clicking the Binoculars icon takes you into the task list selection screen. Information from the maintenance item and the maintenance strategy default into the selection screen. This allows only the selection of task lists that are valid for this maintenance strategy. The equipment and functional location also default in so as to allow the selection of either equipment specific for functional location task lists as well as general task lists. The selection of a task list will populate the cycle area of the maintenance plan with the maintenance packages that are assigned to this task list as discussed earlier. You May also create the task list from the maintenance plan if no suitable task list exists
34. The Scheduling parameters default in from the maintenance strategy The user may populate the scheduling period with any value you wish this will allow you to see the scheduled calls and calls on hold for the period selected. The unit of measure can be set to suit the plan in this case a selection of month may be more appropriate as this is a monthly strategy. The user may also change the scheduling indicator even though this is a strategy created as key date you are able to change to time or factory calendar We have already discussed the requires confirmation check box. The system will prompt for a start of cycle date when the plan is saved this can be entered or left blank. If left blank the prompt will appear again when the scheduling of the plan is carried out. The additional data information was already discussed in the single cycle plan this information is the same in all plans It is important to note when the plan is saved it is still not useable until the scheduling of the plan is carried out.
35. When Scheduling a Time based plan for the first time three options exist Start A dialog box appears input the date which you wish to have the cycle start this date may be in the future or the past. The date will be the date the first cycle will start, in the case of a monthly cycle if the start date is Jan 01 the first call will be 30 days later. Manual Call This will generate a call object on a one time basis each time the user selects this option The dialog box for date will appear this date may be set in the future but can not be set in the past. The date selected is the date assigned to the call object. Start In Cycle This function will allow the user to start a maintenance plan that has multiple packages at any point in the package assignment. The dialog box appears asking for a confirmation date this is the date the last maintenance was performed usually the current date. The offset date may be enter directly here or selecting a package This plan has 1 month, 6 month and 12 month cycles assigned when the select package button is clicked a screen appears with the package assignments. The 6 month package was just completed. Select that package and click the set start offset. A return to the scheduled calls screen shows 1 cycle start hold and 4 scheduled hold calls for package 1 the one month cycle followed by a scheduled hold for cycle 3 the 12 month package. Save the plan to complete the scheduling.
36. The rescheduling of time based plans presents the same options as performance based. Restart A dialog box appears to select what to do with all on hold calls the standard option is to select delete or the user may select skip if you require a history to be maintained A dialog box appears this time asking for a date for the start of the cycle. This date may be in the past or the future. This date will be the date the Cycle will start from. Start In Cycle This Again the dialog box appears to select what to do with all on hold calls The functionality beyond hear is the same as the start in cycle for a new plan
37. The multiple counter plan will link two different characteristics like operating hours and time to generate preventive maintenance work. 200 operating hours or three months. This plan has no strategy assigned task lists used for multiple counter plans can not be assigned to a strategy Result no operation will be selected when the order is called. The only input required on this screen is the Maintenance plan category in this case we will choose Maintenance Plan to order. This description is set in the IMG Cycle sets may also be used to create multiple counter plans for devices that have more than one counter of the same unit. At Sask Power we have a number of line protection breaker these unit are self contained three Pole units with a counter on each pole all three poles will be maintained if one pole triggers the cal,
38. Complete The text Description of the Maintenance plan in the Plan header. Move to the maintenance item section of the maintenance plan All th information is this area has been discussed prior
39. When creating a multiple counter plan the user will enter the cycles and units for the cycle. In this case we have a counter that records operating hour and we have a time based cycle. The binoculars icon will default the counter information from the technical object in the maintenance item The I icon displays the counter information
40. The decision as to whether both cycles have to be reached or either one of the two may trigger a call If the cycle modification factor if used will apply to all cycles The information contained on the additional data tab has been discussed previously and remains the same for all types of maintenance plan. The plan is now ready to save. Again until scheduled the plan cannot generate a call object.
41. The start icon is the only scheduling function available when the plan is initially created. Clicking this icon will schedule the plan based on the current counter readings of the object and or the time based cycle. If the time based cycle will trigger a maintenance call prior to the when the counter will trigger a call the on hold call will will be as a result of the time base cycle.
42. The only option available for rescheduling of multiple counter plans is Restart. When restart is selected the dialog box appears to select what to do with all on hold calls. When a decision is made the system the reschedules the plan based on current counter and time based cycles.
43. A seasonal or specialty maintenance plan can be created using any strategy or cycle set currently in the system The call object can be any one of the three previously described
44. The maintenance item for Specialty plans is identical to all the other strategy type maintenance plans. The seasonal plan may also use am cycle set to determine the cycles in the maintenance plan. In this case we have a weekly strategy. As with all other strategy type plans a task list must be assigned to the maintenance item.
45. When setting up the scheduling parameters the user must select Time Factory Calendar in the scheduling indicator if using a regular strategy a factor calendar must be entered if using a cycle set the factory calendar can be assigned to the cycle set and will the default here. The factory calendar displayed has defined all days as work days from May 1 to September 30 this means the plan will only generate call objects during that period. Factory calendars are created and maintained in customizing. Factory calendars can be created such as the is that has only one work day each month that being the first work day of the month when a holiday calendar is included with a factory calendar if the first work day of a month falls on a holiday the next day will be set as the first work day. Maintenance plans can then be generated on the first work day of the month. The creation of these calendars will allow the user to create a personalized custom schedule for maintenance.;
46. Specialty pans are scheduled the same way as any other strategy plan The user has the option of Start , Start in Cycle and Manual Call as options to for the initial scheduling. Manual call is available anytime for maintenance plans. The Rescheduling of these plans is the same as any other strategy plan as well.
47. The selection screen provides the ability to select a range of maintenance plans by several criteria. The multiple selection for maintenance plans brings in the complete search criteria for maintenance plans. The sort field may be very useful to make selection here. The date range provides the ability to provide long range cost estimates for preventive maintenance. The plans included in the costing are those that have calls on hold for the period selected. Performance base plans on hold status is determined by the annual estimates for the counters of the technical object. The costs are determined by the details included in the task list for labour hours resources and components assigned. The greater the detail in the task list the better the costing information will be. This transaction may be run in backround. The following are available only after running in backround Selected Maintenance Plans Displays the maintenance plans considered by the system during the last costing performed by the user. Display Costing Displays costing with the expected costs from planned maintenance in the specified analysis period. Last Error Log Displays the error log for the last costing. Administrative Data Displays the date of the last costing saved.
48. The display is returned in the list viewer format. This provides the user with a great deal of flexibility in creating their own view with the appropriate sub totals and totals All information can be exported to local files directly to Excel the same as all standard lists
49. This transaction will call and reschedule maintenance plans automatically. The transaction can be run manually in the fore ground or scheduled to run in back round. Maintenance Plan The system generated or user defined number of a maintenance plan Maintenance Plan Cat The call object to be generated for a maintenance plan(Order, Notification, or Service Entry) Maintenance Plan Sort Field Value set in customizing to to provide a selection group for maintenance plans Maintenance Strategy The unique key used to identify a maintenance strategy Call Objects For The Next N Days Controls the period for which the system will generate call objects(orders, notifications and service entries) for on hold objects The interval will be the system date deadline monitoring is run plus this number of days. Call objects are generated for all plans that have a call date with in this interval. Reschedule Incl. This this indicator is defaulted in the standard system. The system reschedules the plan to ensure at least one on hold call exists in each maintenance plan Immediate Start For All Indicator for the immediate scheduling of the maintenance plans selected(would be used in for ground processing) If you want to schedule all the maintenance plans selected straight away, select this field. If you first want to choose the maintenance plans that are to be scheduled from a list, leave this field blank.