Chapter 6System Test, Evaluation, and

Validation

•April 2012

Aims of this Lecture

• To understand the process of system test, evaluation, and validation

• To discuss how to write a system test report

What is …

• The examination and assessment of a system (or an element of a system) in terms of relative worth, quality of performance, degree of effectiveness, anticipated cost, and so on

Categories of testing

• Various categories of testing are identified by program phase, and the effectiveness of the evaluation effort increases when progressing through types 1, 2, 3 and 4 testing

Type 1 testing• During the early phase of detail design, breadboards,

bench-test models, engineering models, engineering software, and service test models are build with the intent of verifying certain performance and physical design characteristics. These models, representing either an entire system or a designated system component, usually operate functionally (electrically and mechanically) but do not by any means represent production equipment. In the development of software, the application of rapid prototyping is sometimes used to verify design adequacy.

Type 2 Testing • Formal tests and demonstrations are

accomplished during the latter part of detail design when preproduction prototype equipment, software, and similar to production equipment (that which will be deployed for operational use), but it is not necessarily fully qualified at this point in time. A test program may constitute a series of individual tests tailored to the need. Such a program might include the following:

Type 2 Testing

1. Performance tests are accomplished to verify individual system performance characteristics. For instance, tests are designed to determine whether the electric motor will provide the necessary output, whether the airplane will perform its intended mission successfully, and so on. Also, it is necessary to verify form, fit, interchangeability, product safety, and other comparable features.

Type 2 Tesing

2. Environmental qualification – temperature cycling, shock and vibration, humidity, wind, salt, spray, dust and sand, fungus, acoustic noise, pollution emission, explosion proofing, and electromagnetic interference tests are conducted. These factors are oriented to what the various system elements will be subjected to during operation, maintenance, and during transportation and handling function.

Type 2 Testing 3. Structural tests are conducted to determine material

characteristics relative to stress, strain, fatigue, bending, torsion and general decomposition.

4. Reliability qualification are accomplished on one or more system elements to determine MTBF. Also, special tests are often designed to measure component life, to evaluate degradation, and to determine models of failure.

Type 2 Testing

5. Maintainability demonstration – tests are conducted on one or more system elements to assess the values for mean active maintenance time (M), mean corrective maintenance (Mct), mean preventive maintenance time (Mpt), maintenance labor-hours per operating hour (MLH/OH), and so on.

Type 2 Testing 6. Support equipment compatibility tests are often

accomplished to verify compatibility among the prime equipment, test and support equipment, and transportation and handling equipment.

7. Personnel test and evaluation are often accomplished to verify the relationships between people and equipment, the personnel quantities and skill levels required and training needs, both operator and maintenance tasks are evaluated.

Type 2 Testing 8. Technical data verification – the verification of

operational and maintenance procedures is accomplished.

9. Software verification – the verification of operational and maintenance software is accomplished.

Type 3 Testing

Formal tests and demonstrations, started after initial system qualification and prior to the completion of production, are accomplished at a designated field test site by user personnel, operation.

Type 4 TestingDuring the operational-use phase, formal tests are sometimes conducted to gain further insight in a specific area. It may be desirable to vary the mission profile or the system utilization rate to determine the impact on total system effectiveness, or it might be feasible to evaluate several alterative support policies to see whether system operational availability can be improved.

Planning for Testing and Evaluation

1. The definition and schedule of all tests requirements, including anticipated test output for each individual test and integrated where possible.

2. The definition of organization, administration and control responsibilities.

3. The definition of test conditions and maintenance and logistic resource requirements.

Planning for Test and Evaluation

4. A description of the test preparation phase for each type of testing method, training of testing.

5. A description of the formal test phase.

6. A description of condition and provisions for a retest phase.

7. The identification of test documentation.

Preparation for system test and evaluation

• The selection of the items to be tested,• Establishment of test procedures,• Test site selection,• Selection and training of test personnel,• Preparation of test facilities and resources,• Acquisition of support equipment,• Test supply support.

Test performance and reporting

• This requires operating and supporting the system in a prescribed manner as defined in the system test and evaluation plan.

Test performance and reporting • The following questions will be answered:

1. what is the true performance and effectiveness of the system?

2. what is the true effectiveness of the maintenance and logistic support capability?

3. are the initial specified requirements being met?

Test data requirements1. It provides ongoing data that are anlyzed to ev

aluate and assess the performance, effectiveness, operation, maintenance, logistic support capability, and so on.

2. It provides historical data that are applicable in the design and development of new systems having a similar function and nature.

Development of a data subsystem

1. Success data constitute information covering system operation and use on a day-to-day basis.

2. Maintenance data cover each event involving scheduled and unscheduled maintenance.

Test reporting 1. The final effort in the evaluation process,

2. It should reference the initial system evaluation planning document,

3. It should describe all test conditions, incorporated system modifications during the test, test data, and the results of data analysis.