Enclosures

(and your hull packing work). You must stress to your

ENCLOSURES

workers how system essentiality, in an operational

environment, equates with mission capability and

You will find a lot of documentation inside the CWP

personnel safety. In other words, workers must

when it arrives at your desk. Inside will be process

understand how the work they perform in a maintenance

instructions, plans, technical drawings, and instructions

or repair environment can seriously affect the

pertinent to the production job at hand. Documents listed

operational capabilities of the tended unit as well as the

as references are not intended to be included in the CWP,

safety of the personnel aboard the unit. This is where the

but they must be available when required. You will also

assigned levels of essentiality, assurance, and control

find a copy of applicable portions of references included

come into play. What do we mean by these terms? We

in the CWP. In addition, the 4790/2R, Automated Work

will discuss each in the following paragraphs.

Request, is included within the CWP to provide for

complete documentation and references back to the

originating tended unit. You will use all of the

LEVELS OF ESSENTIALITY

documentation to perform the maintenance action,

production task, or process assigned to your work center.

A number of early failures in certain submarine and

surface ship systems were due to the use of the wrong

REVISIONS

material. This led to a system for prevention involving

levels of essentiality. A level of essentiality is simply a

You can make minor corrections, to the work

range of controls in two broad categories representing a

procedure (as directed by local instructions) as long as

certain high degree of confidence that procurement

they do not change the scope of the work being

specifications have been met. These categories are

performed. However, you must initiate a revision when

verification of material, and

it becomes necessary to change the original scope of the

job, such as a part not originally intended to be worked

confirmation of satisfactory completion of tests

on. The revision cover sheet gives exact instructions on

and inspections required by the ordering data.

adding, deleting, or changing steps in the work

sequence.

Levels of essentiality are codes, assigned by the ship

according to the QA manual, that indicate the degree to

ADDENDUM

which the ship's system, subsystem, or components are

necessary or indispensable in the performance of the

Depending on the complexity of the task, it may be

ship's mission. Levels of essentiality also indicate the

desirable to have two or more work centers working

impact that catastrophic failure of the associated part or

portions of the task concurrently. Planning and

equipment would have on ship's mission capability and

estimating (P & E) will initiate an addendum to the

personnel safety.

original CWP. The addendum will include all the

headings of the CWP-references material list, safety

LEVELS OF ASSURANCE

requirements, work sequence, and so forth. When you

complete the work steps, include the addendum with the

QA is divided into three levels: A, B, and C. Each

CWP.

level reflects certain quality verification requirements

of individual fabrication in process or repair items. Here,

LEVELS OF ESSENTIALITY,

verification refers to the total of quality of controls, tests,

ASSURANCE, AND CONTROL

and/or inspections. The levels of assurance are as

follows:

To provide your customers both repair quality and

QA, you as a supervisor of a work center or a work group

Level A: Provides for the most stringent or

in an IMA and your maintenance personnel must

restrictive verification techniques. This

understand and appreciate your customers and their

normally will require both QC and test or

operational environment. This will require that you and

inspection methods.

your personnel give serious thought and consideration

Level B: Provides for adequate verification

to how a system's nonperformance may endanger

techniques. This normally will require

personnel safety and threaten the ship's mission

limited QC and may or may not require

capability. For example, you are not going to be aboard

tests or inspections.

the submarine as it does its deep dive to test hull integrity

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