The Manage Maintenance Program process consists of the following sub processes:
This sub process handles the definition of preventive (interval based) maintenance plans and condition based maintenance.
For each serial part number, one or more maintenance groups can be defined. A maintenance group is identified by a certain operational condition (such as long distance or short distance, very hot weather or very cold weather). Depending on the operational conditions the need to perform preventive maintenance may differ. The intervals for the preventive maintenance can be defined in any of the operational parameters that are available for each maintenance group, and also with a calendar interval. All operational parameters that are defined for the serial part would normally be present in each maintenance group for that specific part, and each maintenance group can in addition have more operational parameters that are relevant to that particular operational condition. Each interval is defined for a maintenance code. One maintenance code can have one or more operations (instructions) connected to it, and each maintenance code serves as a grouping of operations that have to be done within a certain interval. The maintenance plan for each maintenance group can consist of an unlimited number of intervals. The use of a maintenance code having been set to Cycle will terminate the maintenance plan, and start all over again.
The maintenance program for one vehicle can differ considerably from that of another vehicle. Depending on maintenance access and the criticality of a certain part, the maintenance program might include on-condition maintenance. The idea behind this type of maintenance is to take measurements to establish the operational state of a part or system. This can be done by ordering the vehicle to maintenance on a certain schedule or by automatically monitoring the vehicle using built-in test equipment. The condition limits describe the conditions that should be monitored for each serial part revision with limits and recommended monitoring intervals. You can monitor any number of conditions for the components defined as serials. The main principle is first to define the conditions that need monitoring. Normal values, warning limits, danger limits, and change (critical) limits between two concurrent measurements are defined. If any of these limits are exceeded upon measuring, a warning and danger signal is issued.
This sub process handles definition of fault deferral rules. These rules are used to defer non-critical faults. The set of rules manages what kind of faults that can be deferred and on what type of material. A fault can be deferred in a combination of operational interval and calendar, and requires approval before it becomes effective.
Instructions indicate what should be done for the different types of maintenance tasks. This is indicated in terms of the number of maintenance operations (check points) for each maintenance object and function in the product structure, the kinds of maintenance tasks on which these should be performed, and the consumables, repairable, and components (rotable) that are needed. For each operation it is possible to define required material, tools and facilities, zones and access panels, sign off requirements, criticality and condition measurements.
Instructions are commonly broken down into more detailed activities often referred to as subtasks. Subtasks can be defined and used on task types such as interval maintenance, modifications, LLPs, condition limits and faults. The subtask will contain similar information as the instruction. Examples of information common to subtasks and instructions: Type of operation and the location at which it is to be performed, functional breakdown, execution phase, competence requirements, material list, tools and facilities, zones and access panels, and signature requirements.
It is also possible to define a network
of instructions and subtasks within a given maintenance task code. This is done
by defining predecessors for instructions within a task code and for subtasks
within an instruction, which would then represent the optimized sequencing of
task codes to be performed within a maintenance visit.
Instructions support RCM (Reliability Centered
Maintenance) analysis in that they can receive data from such an
analysis. Some basic data must still be added. Instructions
may also be added without RCM analysis.
Stress ratings are used to indicate under which stress or tension (thrust) the system is used. Stress ratings are typically entered for the top template part of a structure but they can also be entered on a lower template level in the structure. One of the stress ratings can be set to be the default, which means that the serials are automatically set to the default stress rating if nothing else is specified.
A stress rating has an impact if the template structure contains life-limited parts. Enter life limits for Life Limited Parts (LLPs) based on stress ratings. Life limits can be defined for all template structures that the LLP can be used in and for all stress ratings that are defined for each template. Life limits are entered in operational parameter values. In addition, life limits can be entered in calendar months from the manufactured date and as the maximum number of repairs possible. The number of days forewarning is entered to identify when a maintenance task should be created before the life-limited serial drops dead. Instructions and subtasks can be connected to life limits and sequenced into a logical order for performing the work at a maintenance visit.
This sub process handles definition of a modification and the different types of material that is assigned to the modification. The modification itself would normally origin from one of the following:
The issuer of the modification will state which types of material should be assigned to the modification, and also how important it is to comply with the modification. The different material types equals one or more serial part numbers or revisions within IFS/Vehicle Information Management. The assigned serial part numbers or revisions will again control the actual serial numbers that will have to comply with the modification.
This sub process handles definition of detailed information for each assigned part revision of a modification. The required step of this process (unless you are running IFS/Complex MRO) is to enter the instructions to be performed for the different types of inspections and terminating action that are defined for each assigned part revision.
If the modification requires compliance with another modification, or excludes compliance with another modification, in order to be performed, this must be registered for each assigned part revision.
Inspections can be defined in order to determine whether the modification needs to be complied with or not. Such inspections can be defined differently for the different assigned parts.
If the terminating action has not been defined on the assigned parts it is required to enter intervals for the terminating action.
If you are running IFS/Complex MRO and the modifications will be executed as shop orders, it is required to indicate when definition of affected parts have been completed.
When all detailed information has been entered for each assigned part or revision the modification must be activated, and serials will be assigned to the modification.
Instructions and subtasks can be connected to modification codes and sequenced into a logical order for performing the work at a maintenance visit.
This sub process handles possible changes that can be done to a modification after the modification has been activated without having to create a new revision of the modification. The process also handles de-activating the modification by changing the status to Obsolete, and making it possible to remove the modification.
This sub process handles introduction of changes to template structures by complying with a modification. A modification can introduce new alternates or alter existing alternate definitions for a template structure. A normal type of change would be that an alternate are no longer valid to use after complying with a modification.
A modification can also introduce changes to the configuration of a template structure. The configuration can both be extended (add structure position) and reduced (remove structure position).