The Maintenance Program Definition (MPD) Workbench and Maintenance Event Builder (MEB) are part of the SAP for Aerospace & Defense (SAP for A&D) industry solution. A&D organizations typically use these SAP programs to plan, schedule, and track sustainment programs for aircraft and other complex assets. Detailed maintenance or sustainment requirements, numerous one-time requirements, and specific compliance reporting to various agencies are not, however, unique to this business sector. Any group of large, complex assets that require a detailed approach to defining and executing a comprehensive sustainment program can benefit from these tools, even if the SAP for A&D industry solution is not installed. As long as the business functions I describe are activated and the configuration and master data are set up, an organization can use these processes. Here are some examples of large, complex assets:

• Heavy machinery. Large construction or mining equipment has extensive, ongoing preventive maintenance requirements, along with required safety inspections. The process of developing and tracking a sustainment program in the MPD Workbench and MEB ensures the operational availability of the equipment and facilitates compliance with worker safety regulations.
• Oil and gas refineries. Periodic plant shutdowns for inspection and maintenance of these plants must be carefully planned and executed. Additional maintenance needs identified during the already scheduled work must be incorporated into the shutdown period as quickly and seamlessly as possible to reduce downtime. Adjusting the schedule and evaluating labor capacity impact of the additional work are critical to bringing the plant back online.
• Ships: Maintenance and safety requirements are similar to those of aircraft in terms of the volume of actions to be performed on a single ship, with larger, heavier subcomponents to be repaired and maintained. Combining many of the maintenance actions into a single schedule can help facilitate the return of ships back into service and generates revenue.

The process of developing and managing complex sustainment programs for large, complex assets requires a broad toolset that is tightly integrated with the enterprise shop floor execution and financial reporting systems. SAP ERP Central Component (SAP ECC) 6.04 provides this toolset with the MPD Workbench and MEB. These advanced capabilities, along with functionalities provided through plant maintenance (PM) and Project System (PS), combine to create an efficient and effective business process for planning, scheduling, and executing heavy maintenance operations. They bring together documentation, planning, scheduling, and compliance reporting as the bridge between the sustainment program definition and the compliance verification needed for heavy maintenance. Although original equipment manufacturers (OEMs) provide regular maintenance schedules to ensure safe and efficient operations of their aircrafts, each operator (or airline) is responsible for compliance with the recommended schedules. Three additional sources of maintenance or repair actions identify actions that should be performed as part of a regular maintenance schedule:

• OEM or regulatory agency bulletins: The FAA issues airworthiness directives (FAA-ADs) that define required actions and specify necessary compliance dates.
• OEM available modifications or upgrades: Various OEMs of aircraft components or subsystems often provide available modifications or upgrades that should be incorporated in the maintenance schedule. These typically involve acquiring the necessary parts kit for the work.
• Flight crew reported malfunctions: After each flight, the flight crew documents any malfunctions or inconsistencies in the aircraft operation. The crew might immediately address these issues or defer them until a larger maintenance window for the aircraft.

Each maintenance and repair action, hereafter referred to as a work item, must be documented and its status (e.g., pending, scheduled, completed) tracked. All work items make up the sustainment program for a fleet of aircraft. Each work item can apply to one or more planes and might have a required completion date and a set of execution tasks to accomplish the required work. A work item might be performed on a regular cycle, such as scheduled preventive maintenance or inspections performed after a specified number of operating hours, or just once for each applicable plane — as in the case of OEM bulletins and upgrades. Heavy maintenance processes are very complex and time-consuming by nature. Maintenance planners for a set of aircraft must be able to determine the scope of work to be accomplished, estimate the time the work takes to complete, and estimate the cost of the job. They need to negotiate with the operators (or owners) to determine the work items that need to be accomplished within schedule and budget constraints. The maintenance planners must schedule and document the work actually accomplished, while simultaneously coordinating multiple work items into a combined package of work. To keep the operator confidence, the schedule and the budget estimates need to be as close to the actual time frame and costs as possible, but provide some flexibility for any new work that is discovered during the scheduled visit. The newly discovered work might require the reevaluation of the schedule and budget and may even require renegotiation with the operators. This complex environment commands clearly defined procedures and toolsets not only to provide value to the equipment operator but also to use the maintainer’s resources efficiently. A maintenance planner manages the sustainment program from the beginning of the plan to its completion within the operator’s schedule, budget constraints, and regulatory safety requirements. A toolset to facilitate this process should enable documenting the work items, reusing standard planning data for repeated work, managing schedules for the combined work package, and reporting on compliance. Figure 1 provides an overview of a heavy maintenance process.

• Define a maintenance program: The maintenance engineer identifies and documents various actions (e.g., fluid changes, inspections to ensure proper conditions, optional modifications or upgrades, and required safety actions) that need to be performed. For each action, the maintenance engineer needs to describe the action and develop a set of instructions for performance. These instructions should also include expected findings, acceptable tolerances, and recommended follow-up actions.

• The maintenance engineer must identify the relative timing of each action defined. Some actions might need to be repeated on the elapsed time, triggered by recorded counters, or they may be a one-time event to be performed. One-time events are typical in the aviation industry, in the form of FAA–ADs that specify necessary inspections, any necessary follow-on actions, and documentation requirements. Maintenance engineers must perform an inspection based on a set of specifications, and if they observe certain conditions, they specify follow-on actions. The maintenance engineer documents these requirements in the SAP Document Management System (SAP DMS), using document types configured to support maintenance activities (i.e., maintenance documents).
• Define a maintenance schedule: To define what needs to be incorporated into the maintenance schedule, the maintenance engineer determines which maintenance documents are appropriate for each work item. The maintenance documents provide the maintenance actions that need to be scheduled for the work item over its operational lifespan.
• Schedule maintenance actions: After identifying the maintenance requirements and determining the maintenance documents, the maintenance planner can use standard SAP maintenance scheduling processes to evaluate the current state of the work item in its maintenance cycle and to propose target dates for actions that are due in the planning forecast. The maintenance planner can use SAP operational measurements and observations (i.e., measurement documents) to determine vehicle usage. A common example of this type of measurement is the flight hours recorder on an airplane. The maintenance planner uses this information to develop and negotiate a package of maintenance actions to be performed.
• Plan maintenance events: The maintenance planner reviews the set of maintenance actions from the SAP Maintenance Scheduling processes and prepares a proposed maintenance package schedule. This proposed schedule must include the detailed tasks to be performed, labor and material requirements, and estimated costs as consolidated from the maintenance documents.
• Execute maintenance events: The maintenance planner coordinates the release of the maintenance package schedule, and the work is accomplished.

SAP Configuration Requirements

Before the functional consultant can set up the configuration requirements, the Basis support team must activate the following business functions in the IMG:

• AD_MRO_CI_1, A&D Maint, Repair & Overhaul
• LOG_EAM_POM_2, MEB and Logbook Innovations

Once these business functions have been activated, the functional consultant can begin the necessary IMG configuration. The settings that the functional consultant establishes are the document types that the maintenance engineers use to define the maintenance requirements and work scheduling characteristics of the work package. The maintenance engineer uses Document Info Records (DIRs) in the SAP DMS to capture the details of the overall sustainment program of the fleet. SAP has provided new objects in its enhancement package 2 for DIRs that allow for the capture of maintenance planning data that uniquely support the MPD Workbench functionality. These objects are inherited by lower-level execution objects, such as SAP Maintenance Orders. In the case of a heavy maintenance scenario, the functional consultant must configure three new document types, along with appropriate status values for them (e.g., Created, Released, and Complete). The DIR types are typically:

• Operator’s Maintenance Program (OMP) – the highest level object that defines the fleet of aircraft (such as MD-80s)
• Maintenance Planning Group (MPG) – broken into periodic and routine maintenance (i.e., recurring actions such as 500 flight-hour inspections) and unscheduled and one-time maintenance (such as modifications or upgrades or FAA-ADs)
• Maintenance Planning Object (MPO) – the lowest level that defines the actual work action

The SAP IMG menu path for this configuration is Cross-Application Components > Document Management > Control Data > Define Document Types. Figure 2 shows document type MPO  as configured by the functional consultant. After setting the DIR type header attributes, the functional consultant must create the allowable supplemental objects that can be linked to the DIR. These object links appear as tabs on the DIR master record and store key data for the planning and scheduling processes. Figure 3 shows the object links as configured by the functional consultant (e.g., DRAW, EQUI, and IFLOT). This completes the DIR configuration to support the SAP heavy maintenance solution. The remaining configuration requirements facilitate scheduling the maintenance activities. These settings define logical phases of the execution cycle and the object type characteristics for the maintenance package. They also enable multi-counter maintenance plan features. To define the logical phases of the execution cycle, the functional consultant works with the maintenance planner to identify logical breakpoints in the cycle. A typical aircraft maintenance example consists of the following:

• Depot arrival of the aircraft
• Move to hangar
• Subsystem reassembly
• Subsystem testing
• System testing
• Operational testing

The functional consultant then creates PM/PS reference elements that are used as linkage points between scheduling maintenance tasks and generated maintenance orders to drive scheduling and dependencies. The functional consultant configures these reference elements in the PM configuration. The IMG menu path is Plant Maintenance and Customer Service > Maintenance and Service Processing > Define Field Values for PM/PS Reference Element. The maintenance engineer uses the reference elements with task lists. The next set of configuration settings defines maintenance work order linkages and revision types. To complete the required configuration settings, the functional consultant performs the following IMG tasks: 1.  To enable the order type PM01 as a sub-network (or subordinate) to the PS network type PS04, follow IMG menu path Project System > Structures > Operative Structures > Network > Define Parameters for Networks. This action includes the generated order on the PS network and enables the functional consultant to reschedule the whole network, including the orders. 2.  Next, to create a revision type for MEB Revisions, follow IMG menu path Plant Maintenance and Customer Service > Maintenance and Service Processing > Maintenance Event Builder > Maintain Revision Type. In this example, revision type (Rev.Type) DM is created to represent depot maintenance (Figure 4). 3.  Next, assign a number range to the MEB revision type just created. The number range allows system-generated numbering of the revisions created. Follow IMG menu path Maintenance and Customer Service > Maintenance and Service Processing > Maintenance Event Builder > Maintain Revision Number Range. 4.  Finally, turn on the Enhanced Multiple Counter Plan (Enh. MultipleCounterPlan) enhancement (Figure 5). This setting is required because all MPD-generated maintenance plans will be Multi-Counter Plans, from SAP’s definition, supporting calendar, and counter-based scheduling. Follow IMG menu path Maintenance and Customer Service > Maintenance Plans, Work Centers, Task Lists and PRTs > Maintenance Plans > Configure Special Functions for Maintenance Processing. After completing the basic configuration settings required for use of the SAP-provided heavy maintenance planning and execution toolset, the maintenance planners need to set up the master data necessary to drive the planning and scheduling of the sustainment program.

Master Data Setup

Included in defining a sustainment program is the set of assets (e.g., aircraft) that the organization needs to manage. For the purposes of this article, the maintenance planner creates the functional locations (i.e., the Plant Maintenance technical objects) to represent individual assets and provide a platform to build a serialized as maintained structure that is kept up-to-date as removals and installations are performed. When creating these SAP objects, the maintenance planner should use an appropriate naming convention and structure indicator to ensure consistency among the object identifiers. The ultimate goal is to have a rough-cut schedule for the maintenance event in the SAP system via an operative PS network. This schedule, generated by a standard network, contains the dependencies between the major phases (milestones) and the combined work package. The maintenance event represents the package of work that needs to be performed on a specific work item, at a specific facility, starting on a specific date. To define the necessary maintenance event phases, the maintenance planner can use a Standard Network template to store the dependencies between the phases (i.e., the PM/PS reference elements configuration). Figure 6 provides a sample Standard Network and a set of phases for the event planning. The maintenance planner uses this template later to create a detailed plan for a specific maintenance event. The detailed work steps required to accomplish each proposed maintenance action are captured in detailed task lists (i.e., SAP General Task Lists) and are propagated to each maintenance order that the MEB generates. In defining the full set of steps required, for example, to perform an FAA-required inspection, the maintenance planner needs to include everything that must be executed from the time the aircraft arrives at the facility (i.e., arrival) until the time it leaves (i.e., delivery). To facilitate planning data that can be used in varied scheduling scenarios, the maintenance planner treats each maintenance action as if it is accomplished individually, isolated from the other actions (i.e., the inspections task is separated from the repair task, and the modifications task is separate from the other two tasks). Thus, a standard set of arrival and departure steps is present in the task list for every maintenance action. To reduce the duplicated manual effort to copy specific tasks and manage the larger detailed task lists, SAP provides a Hierarchical Task List (HTL). The HTL is a container for General Task Lists allowing the maintenance planner to create a super set of all operations to be performed to accomplish the required work scope. This super set enables the maintenance planners to build a work plan that is usable, regardless of other work items that happen to be scheduled for the same end item. The maintenance planner creates the individual General Task Lists, writing each task so that it can be reused for a maintenance work item that needs the same tasks performed (e.g., a landing gear replacement). The maintenance planner then adds the task lists to the HTL container. For the A&D example, the HTL for a landing gear replacement would include immobilizing the aircraft and jacking it up, in addition to the work on the landing gear (Figure 7). When creating the General Task Lists, the maintenance planner specifies the appropriate PM/PS reference element on the task list header. The reference element provides the link between the maintenance order generated by the MEB and the proper scheduling activity (i.e., Arrival), as shown in Figure 8. The final setup action is to create a link between the work centers in the task lists and the work centers needed for the maintenance orders. The MEB employs a Plan Once, Use Many Places approach to task-list-to-maintenance-order replication. Using transaction MEBOR to establish this link, the maintenance planner can use a single task list to plan and schedule work that might be executed at several locations. This linking capability is referred to as Central Task Lists. Because this step affects work executed at several locations, it is critical for the maintenance planner to provide specific details for individual tasks, including:

• Plant and work centers for the maintenance location
• Plant and work centers used in General Task Lists
• Resulting target work center and location for performance of the work

For the A&D example, I use a single maintenance planning and execution location. As shown in Figure 9, the MEBOR transaction displays entries to support this mapping (e.g., the Work Center is LGASMBLY, and the Plant is 1002; the resulting work center is LGASMBLY 1002). After all of the necessary SAP configuration and master data have been entered into the system, the next step in the sustainment program is to create the DIRs that describe the sustainment program and facilitate planning and execution.

Document the Sustainment Program

The maintenance engineer documents the sustainment program using DIRs in the SAP DMS. These DIRs are organized by document type (OMP, MPG, MPO). At the top level of the document structure is type OMP (Operator’s Maintenance Program). The maintenance engineer uses the OMP document to separate the planning effort by asset type, customer, or geographic region for the entire fleet or any subdivision. At the next level is the MPG (Maintenance Planning Group) document. This level facilitates the grouping of sustainment requirements of the similar origin, such as OEM Service Bulletins, FAA-AIRs, or Preventive Maintenance Actions. At the lowest level of the structure is MPO. Each MPO document represents a distinct work item, with the applicable technical objects that have been authorized for the work. The MPG documents are not required, but they do provide the capability to easily divide up the overall maintenance program and manage them individually. The required information for each document varies by type. The types lower in the structure hierarchy require additional information to document the specifics of the sustainment program. The MPO document type, which the MPD Workbench uses to generate Maintenance Plans, provides all the parameters necessary to define the cycles (i.e., Notification Type and Task List) that appear on the various tabs of the document. All tabs are visible from the Create/Change Document transactions on the Object Links tab. Figure 10 shows the MPO document content tabs necessary for the MPD Workbench to generate the maintenance plans. In all cases, the starting point is the Object Links tab of the DIR. This tab identifies the individual technical objects created to represent the assets in the maintenance program. In this example, data listed in the Functional Location section represents each aircraft in the fleet. The maintenance engineer uses the Maintenance Cycles tab (Figure 11) to define the repeat factor (e.g., only performed once, weekly, or every 500 operating hours) used to schedule the maintenance cycles by the MPD Workbench. The Plan and Sched Data tab (Figure 12) contains necessary parameters to create the maintenance plan. In the Maintenance Plan Item Data section of the screen, the Task List (or Hierarchical Task List) is identified, so the maintenance engineer can copy it into the maintenance plan when generated by the MPD Workbench. Next, the Document info record tab (Figure 13) lists the documents that are linked to each other to build a hierarchical structure. The MPD Workbench uses these linked and structured documents to create a schedule for the required work items for each aircraft. Document links are created one level at a time, from the lower level up. Therefore, to create a three-level structure, where the OMP is the highest level, MPG the mid, and MPO the low detailed level, the maintain engineer must create the link from MPO to MPG and MPG to OMP. To create a new link, the maintenance engineer selects the document type and document number (i.e., MP and 1000000012) and then presses the Enter key. The system creates the link and indicates the direction of the link (the arrow) to the specific document (Figure 14).

Initialize and Schedule the Sustainment Program Schedule

The MPD Workbench processes the DIRs, which have been created, linked into a structure, and assigned to technical objects in scheduled maintenance plans. These plans define when a described action is to be performed. Beginning at any level of the DIR structure, the maintenance planner uses the MPD Workbench tools to create, review, or report on the status of the sustainment program. Figure 14 The MPD Workbench evaluates the maintenance cycle information stored in the DIRs and then creates or updates the maintenance plan. The system requests the parameters for the maintenance plan with appropriate time intervals (Figure 15). Next, the maintenance planner selects the Process in Foreground or Bankground option. This option determines if the process runs in the foreground or is submitted as a backbround batch job. After clicking the Execute button to generate the maintenance plan, the maintenance planner initiates the proper scheduling by clicking the Start MPs button and then clicking the Run button (Figure 16). The maintenance plan generates the maintenance notifications as defined by the scheduling parameters stored in the MPO documents. The maintenance planner uses the MPO documents to monitor the work status. 

Develop and Schedule the Maintenance Event

The maintenance planner lays out the maintenance event using the MEB, drive by the maintenance notifications generated in the MPD Workbench. With the Maintenance Notifications included in the maintenance event, the respective task list specified in the generated Maintenance Plan generates the Maintenance Orders to schedule and perform the defined work scope. The MEB processes begin with the creation of a revision (i.e., a maintenance event). The revision is the object that represents the work package, and the work package acts as the container for the notifications. The revision establishes the scheduling window for the maintenance event and the operative network used to schedule the event. The revision also points to a scheduling network for the work. To create a revision, the maintenance planner follows these steps: 1. Create an Operative Network using the Standard Network created previously as a model. If the resulting maintenance event needs be managed in an individual project (which is typically the case), then create the Project and Operative Network using the Project Builder (transaction CJ20N). Release the Project to allow the collection of costs (e.g., the labor cost for the maintenance planners). 2. Click the create revision icon on the MEB toolbar (Figure 17) 3. Fill in the fields as needed. For example, as shown in Figure 18, the work item is the Depot Maintenance, the facility is the Denver plant (i.e., 1002), and the start date is 02/01/2012. To save the revision, click the exit icon. 4. To display the list of notifications, click the select notifications icon on the Notification List toolbar (Figure 19) and then click Select Notifications. 5. In the Selection of Notifications screen (Figure 20), specify the selection criteria for the relevant notifications (in this case, the notification date, 10/24/2011) and click the execute icon. 6. The system displays the notifications that match the entered criteria. To build the work content of the revision, drag and drop the notifications into the revision package. As shown in Figure 21, Notifications 10000101 - 10000103 appear in the Revision Work Area. 7. To generate Maintenance orders from the notifications, click the create orders icon on the Revision Work Area toolbar. The MEB creates an order for each task list referenced in the Notifications (Figure 22). If the Notification references an HTL, duplicate Task Lists are automatically dropped from the order generation process. After the orders are created, the maintenance planner needs to assign the orders to the appropriate network activity, using the PM/PS Reference Element, which was specified in the Task List, and the Network Activity, which that was noted in the revision attributes. Then the maintenance planner schedules the revision. To assign the orders to a network: 1. Click the revision icon on the Revision Work Area toolbar (Figure 19) to select a Revision. The entire line is highlighted (i.e., Revision 6 as shown in Figure 22). 2. Click the order assignment to project icon on the Revision Work Area toolbar to assign the order. 3. Click the schedule icon on the Revision Work Area toolbar. This action copies the network activity start dates to the Basic Start Date for the linked orders. This date is inherited from the Revision Start Date specified on the Revision Header. Completion of individual maintenance orders triggers standard SAP ECC functions related to maintenance plans, such as scheduling the next maintenance call according to the established parameters and setting the planning up for the next due date for the maintenance action defined by the DIR.

Execute the Maintenance Event

Now that maintenance orders have been created, the maintenance planner uses standard SAP features in the PM module to release and execute the defined work in the maintenance orders. Normally, maintenance facilities have production control departments that release work orders to the shop floor workers at the appropriate time. The actual release date is coordinated to work force scheduling and material kitting.