Instructions and Subtasks

Introduction

The functionality for instructions in IFS/Vehicle Information Management (IFS/VIM) can be used to plan and prepare the work, i.e., maintenance, for a serial. This functionality is useful as serials are constantly utilized, for example, within a fleet of Aircrafts you operate, and require maintenance on a regular basis. Instructions (task cards) indicate what should be done for the different types of maintenance tasks (i.e., interval maintenance, modifications, condition limits and faults). An instruction is a complete job that is to be carried out as a part of a larger maintenance activity, e.g., to replace the main landing gear as a part of a C-check or Major overhaul. The instructions live their own life independent of other instructions within the maintenance activity, but they can be sequenced to optimize the work flow. However, these instructions are commonly broken down into more detailed activities often referred to as subtasks. It is possible to connect several subtasks to an instruction to describe how the instruction should be performed. A subtask then becomes the actual object that the work execution is controlled by, and enables work in progress monitoring by instructions. The subtask will contain almost the same information as an instruction. These are as follows:

Instructions are revision handled and status dependent. The purpose of this feature is to ensure that changes to task cards can be defined while an old revision is still being used, as well as allowing different definitions for different customers or users. With the status management feature on instructions, it will be possible to control which task cards should be included in a work scope. Valid statuses are: Preliminary, Active and Obsolete. Any number of instruction revisions can be of any status at any point in time. However, note that only one revision of each instruction can be used within a maintenance program.

Instruction revisions are defined for valid part revisions. You can have several revisions for each instruction, where each revision is to be used in the connection between task codes and instructions, and between instructions and subtasks. Through an instruction revision, you can define information on the operations that are to be executed when the serial(s) for the selected part revision is to be maintained. This information will include, What, Where, and the Workload of the instruction or subtask. Once this information is defined, you need to enter the material needs, and tools or facilities that are required for the execution of the instruction or subtask. In addition, the instruction (operation) can be defined with a criticality, for instance, if the operation is important for the stability of your part, you should preferably select the criticality type Operational Stability with a criticality level of Important. The following table shows the valid criticality codes and levels that can be used when you want to define how critical an operation is:

  Criticality Code Criticality Level
1) Safety Not Important
2) Cost Slightly Important
3) Comfort Important
4) Operational Stability Very Important

Only instruction revisions that are in either the Preliminary or Active status can be connected to task codes. You need to specify the task types to which you want the relevant instructions or subtasks to be included. Valid task types can be interval maintenance tasks, condition based maintenance tasks, modification tasks and fault tasks. At the time of distribution, only active instruction revisions will be distributed to work orders.

Instructions and Subtasks for Interval Maintenance Tasks

Maintenance codes are connected to the maintenance plan which is defined for your part revision. This definition will group the interval based maintenance tasks in the maintenance plan, and indicate how often the maintenance is to be performed on your part revision.

To define maintenance instructions for this task type, you need to connect an instruction (operation) to the maintenance code you want. Accordingly, when a interval maintenance task is created for this maintenance code, the connected instruction (operation) will be used to execute the maintenance.

Maintenance 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 (rotables) that are needed.

Instructions and Subtasks for Condition based Maintenance Tasks

To make use of an instruction (operation) for a condition based maintenance task, the instruction must be connected to a condition limit. These on-condition instructions are defined per condition category and condition code. When the condition based maintenance task is due, the connected instruction (operation) will be used to execute the on-condition maintenance. 

Instructions and Subtasks for Modification Tasks

To define a modification instruction, select a connection type when you assign an instruction to the modification (i.e., the modification which is defined for your part revision). When a modification task is due, the connected instruction (operation) will be used to execute the modification maintenance. The following table shows the valid modification execution types for instructions:

Modification Execution Type Description
Initial Inspection When you connect an instruction to the modification using this execution type, this will be the instruction used to execute initial inspections.
Continued Inspection When you connect an instruction to the modification using this execution type, this will be the instruction used to execute continued inspections.
Terminating Action When you connect an instruction to the modification using this execution type, this will be the instruction used to perform the actual modification (i.e., when complying or embodying the modification).
Decomply If decompliance is allowed for your modification, you can select this execution type to use the connected instruction (operation) to reverse or in other words undo the modification.

 For more information on the modification execution types, refer the online help file: Modification Details/Instructions.

Instructions and Reliability Controlled Maintenance (RCM)

The RCM function is used to analyze maintenance related data in order to identify and handle hazardous areas, or areas you want improved within, for instance, your fleet. When an RCM analysis is performed, the instruction is used to receive data which you can evaluate. Prior to this certain basic data is required to be defined. Note: Instructions can be added without RCM analysis.   

When a serial part is modified (e.g., through a re-design or technical change), this part can be given a new revision if any of the changes influence the instructions. As a result of this, during the modification phase, some of the serials will consist of the old part revision while the other serials consist of the new revision. For such an occurrence, you have the option of copying valid instructions. These are the instructions for the functions and components (1) that have changed (2) are required to be changed (3) have been removed (4) have been added. The following diagram shows a graphical display of this scenario:

AboutInstructions1.gif (7860 bytes)

For information on copying instructions to a part revision, refer the activity Copy information from another part Revision.