For each maintenance operation for a part revision, the specific operation (instruction) that should be performed is registered. For each operation, the following information is entered: type of work, competency requirements, number of persons and the hours needed to execute the operation. For each operation, there can be a connected list of materials, tools and facilities, documents (such as drawings or a description of the work), criticality, and the function (system) to which the work applies.
An instruction can be connected to a maintenance code (interval based maintenance) indicating what type of work the instruction should be associated with and the interval between each execution of that work. Instructions may also be connected to on-conditions and modifications.
Due calculations for interval based maintenance work through the serial's maintenance plan and calculate due dates for all maintenance codes in the plan. For every calculation rule except Special Case, the due date is calculated based on the value since overhaul for the serial's operational parameter. For the Special Case calculation rule, the due date is calculated based on the total value for the serial's operational parameter. The average value per month for the operational parameter per maintenance group is used when calculating due dates. The average value per month is not used for the Manufactured Date and Installed Date calculation rules, and therefore there will be no problems with task calculation for maintenance groups with only these calculation rules even when the average value does not exist. If the calculated due date is within the defined number of days forewarning in the maintenance plan, a pending task will be created. For more information, refer the online help file Interval Based Maintenance Programs.
It is possible to establish an on-condition monitoring program for a part revision. You define a condition with warning and danger limits and intervals for measurements to take place. You can also define a change limit for a measurement. Reported measurements exceeding a limit will create a pending maintenance task for the part revision. For more information, refer the online help file Condition Based Maintenance Programs.
The need for modifications typically arises as a result of new technology, safety demands, quality demands, etc., that the manufacturer of an equipment has specified or developed (as a Service Bulletin), or because of repeated errors or damages. It may also be a result of required changes issued by the authorities (as an Airworthiness Directive). A modification leads to an occasional maintenance task that will be executed, within certain time limits, on all or selected serials. The modification process can also be used to control other types of one-time tasks that will be executed on all or some serials. In the period a modification program lasts, the different serials and serial structures will have different revisions on the documentation if the modification leads to changed functionality. The modifications must therefore be seen in close relationship with revision handling on parts, template structures, serials, and serial structures with related documentation. The calculation of modification tasks will calculate the due date of the modification or inspection for serials that are defined as To Be Performed. The calculation is done for each assigned serial based on the Average Operational Value per Month, the Effective Date and the defined Executions (Initial Inspections, Continued Inspections and Termination Actions) for the modification. If the calculated due date is within the defined number of Days Forewarning, a pending task will be created. For more information, refer the online help file Modification Programs.
Some faults are allowed to delay before they must be corrected. For these faults, fault deferral rules must be set up. For more information, refer the online help file Fault Deferral Rules.