What is Developmental Test and Evaluation?
Developmental Test & Evaluation (DT&E) refers to testing performed on components and subsystems designed for use on U.S. defense platforms. This testing is conducted at various stages in the development and acquisition process to verify that the product meets specified levels of performance.
DT&E is normally conducted by the designer of the equipment. These tests are usually performed in a laboratory setting. DT&E should not be confused with operational test and evaluation that is performed on full up military platforms in representative field settings.
DT&E can be used to verify and validate designs of components and subsystems. This can include product improvements, and integrations of hardware and software.
When labratory testing may not be feasible, DT&E can include modi eling, analysis, and simulation.It encompasses the use of models, simulations, testbeds, and prototypes or full-scale engineering development models of the system.
Properly Executed DT&E is Essential
Properly conducted, this testing can decrease the costs and scheduling requirements of failure in Field/Fleet testing. It also serves to demonstrate that the design and development process is complete. Effective Developmental Test and Evaluation can, by catching materiel deficiencies early on, allow sufficient time for required design modifications.
This can reduce the overall program costs. This is because the product will more likely survive the predicted environmental stresses and meet operational requirements. The Defense Science Board Report, Test and Evaluation Capabilities, December 2000 estimated that correction of defects added 10 to 30 percent to system costs.
MIL-STD-810 is an effective standard for Developmental Test and Evaluation, that when properly employed can provide evaluation of environmental factors throughout a product’s life cycle. It is a collection of 29 laboratory test methods with numerous procedures.
The standard has stressed with increased emphasis the need for tailoring test parameters and durations to effectively evaluate these factors. It has had to do so because of the reluctance of industry to initiate the required management and engineering processes. In essence, it is easier to test to cookie cutter specifications that to assess the actual severities of environmental stresses.
MIL-STD-461 is an EMI/EMC standard for developmental test and evaluation. This standard is broken out into nineteen various methods. These methods include Radiated Emissions, Conducted Emissions, Radiated Susceptibility, and Conducted Susceptibility.
MIL-STD-461 testing includes radiated and conducted test methods. These methods involve simulations of magnetic, radio frequency, Electrostatic Discharge (ESD), and Electromagnetic Pulse (EMP) sources of potential disturbance. Susceptibility requirements are determined by type of equipment, type of platform the equipment is to be operational on, and location of the equipment on that platform.
MIL-STD-1275, Characteristics of 28 Volt DC Input Power to Utilization Equipment in Military Vehicles, specifies test methodologies that simulate the nominal 28 VDC voltage characteristics in military ground vehicles power distribution networks. General Requirements for Equipment Under Test (EUT) include; Operational Voltage Ranges, Transient Waveforms, Ripples, Spikes, Surges, and Starting Disturbances.
This standard is used to evaluate a product’s ability to operate as specified when powered in an aircraft power distribution network. MIL-HDBK-704-1 thru -8 define the test methods and procedures. These each of these documents cover a specific power type such as; AC 60 Hz, AC variable frequency, AC 400Hz, as well as tests for DC power equipment.
MIL-STD-1399 Parts 1 and 2
As with equipment designed for use in aircraft and land vehicle, there are electrical compatibility requirements for shipboard equipment. This standard provides test methodologies to ensure that these products meet requirements for operating in extremely noisy electrical power networks.
Compliance by Analysis
In many cases products can be assessed to be compliant by analysis. This is particularly of value when the product to be tested is too large to be feasibly tested in a laboratory setting, or when such testing is deemed to be unsafe. Compliance by Analysis methods can also be used to identify potential design deficiencies early in product development, giving ample time for required modification.
Compliance by analysis can involve any of the following:
- Computer modeling and simulation – This testing is normally done early in product development to assess potential design vulnerabilities so that required design modifications can be undertaken as soon as possible. This method is particularly well suited for the evaluation of the product to dynamic (vibration, resonances, and shocks) and thermal stresses.
- Acceptance by Similarity – This method can be used where the product is nearly identical to products already tested, and there is no reason to believe that differences would pose environmentally induced issues.
- Testing of Coupon Samples – In certain cases there can be significant savings by using coupon samples instead of entire systems. This is of particular value in the assessment of specific materials and coatings.
CVG Strategy Test and Evaluation Expertise
CVG Strategy Test and Evaluation experts have decades of experience in developmental test and evaluation. We can assist you in developing a test program that will reduce risks associated with product failure and required redesign.
Our product test experts can perform a product life cycle analysis to tailor test methods in MIL-STD-810. We can perform engineering analysis to identify potential design deficiencies prior or in lieu of testing Furthermore, our test and evaluation team can manage evaluation programs, write test plans, witness testing, and create test report summaries. We have decades of experience in environmental and EMI/EMC testing in both commercial and military applications.
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