Homework 1 – Lesson 16
Test Objective
Test Scenarios/Set-up
In the lab test, the SRAW will be fired 30 separate times, with variables set at constants. Each test will be evaluated on a yes/no scale for missile launch, missile arm and target hit. In field test, with SRAW being fired 30 separate times. There will be variables within the criteria of target range, target course, and target speed. Each test will be evaluated on a yes/no scale for missile launch, missile arm and target hit.
A successful test will be defined as a positive missile launch and target hit being at a distance of 16 meters. An event failure will be defined as no missile launch or the target not being hit. A successful test series will be defined as successive positive missile launches with targets being hit.
Test Article Configuration
Two tests will be conducted a lab and a field. The lab test will be 30 events (trials) of firing 30 missiles. All targets will be set at a 16-meter distance, standstill, at a target compass of 45. For the field test, the test article will be one marine and the SRAW in a “live” scene, with variables to match this ideal, such as movement. Only one marine will be used in order to reduce the variable of shooting capabilities between personnel. The targets will be moving between speeds of 0 and 30 kilometers per hour, with the degree of the target compass heading between 45 and 280. These will be paired randomly, as well as randomly selected, in order to reduce the likelihood of bias within the test and its results. For tests, built-in test, built-in test equipment and automated test equipment will be used and evaluated prior to these tests. These three components will allow for data to be collected during the development process, enable efficient and economical production to access and measure the acceptance parameters, and to test for fault isolation of circuits.
Test Article and Target Requirements
30 targets and 30 bullets will be needed for the testing, and one marine with prior tested shooting capabilities. All targets will be set at 16 meters, as this is the minimum safe distance for an SRAW. This is needed for both the lab and field test. For the lab test, the target compass will be at 45 for all trials. For the field test, the directionality of the targets will vary, with the angle of the radius of the shooter to the target, varying between 45 and 280. Angles will be randomly selected, in order to reduce biases within the test. These angles will also be randomly paired with speed variations of the target, moving between 0 and 30 kilometers. For cost efficiency, in this first test a smaller sample will be taken, thus a lower confidence level. If proven successful, arguments can be made for increased spending.
Confidence Levels
A cumulative binomial distribution will be used to base the test data off of a nomograph. Using this will set the requirement of a minimum 80% confidence level with a 90% performance level. Thus, there will be 30 trials (30 missiles fired) and only one failure can be assumed to meet these requirements. The advantages of this are that the result of each firing is independent from other events within the test, producing the probability of success for each event to be constant. For test reliability, test-retest will be used. With the same shooter performing in every trial, other tests will not be needed such as inter-rater reliability. This is an advance, because the reliability will be testing the SRAW’s accuracy within the variables listed, leaving out other, unnecessary variables, such as multiple shooters. However, the one shooter should have the reliability in his skills accounted for. Thus, beforehand, his reliability should be tested beforehand in test-retest. This will be used for both the lab and field test.
Test Limitations
The testing of the shooter’s capability needs to be measured and accounted for. Ideally, a larger sample size would be used (more trials), however for this initial trial test will be sufficient in measuring the capability of the SRAW and indicate if and where corrections were needed. Another test limitation would be unpredictable environmental conditions, which can vary between trials, such as wind speed. This cannot be altered or controlled due to test being live, but should be noted. Another test limitation to this is the distance of 16 meters, as this is our primary concern. These tests will allow for the consideration of SRAW to be used at the minimum safe engagement range, but does not measure the SRAW’s minimum range of 17 meters. As this minimal requirement needs to be assured first, the variable of distance must be held at a constant. The limitation in this is that further testing would be needed to ensure the SRAW minimum range of 17 meters, to ensure additional safety measures.
Homework 2 – Lesson 18
A1.
The three most important conclusions are within the three missed hits, out of ten, in the SRAW test. The first is seen in shot 4, where there was no missile launch, arm or hit due to hangfire, leading to corrections needed for prevention in the field. This is a serious cause for concern, as it can result in serious injury. Considering this, it needs to be investigated as to why this occurred. The second is seen in shot 7, where the target range is 612 (2nd farthest), with a missile arm but no hit. The reason this causes suspicion is due to shot 3, where the target range is further (637) and the target speed is at 10, compared to 0 in the previous, without missile arm but hit. This discrepancy leads to further evaluation to be needed. The third is in shot 9, which resulted in a solider injury. There needs to be preventative measures taken in order to reduce the likelihood of the situation reoccurring.
A2.
The top three reasons for placing the SRAW into deficiency status would be,
issue of hangfire in shot 4,
discrepancy between accuracy of SRAW between shot 7 and shot 3, and
occurrence of solider injury in shot 9.
The incidents named within 1 and 3 above, show severity within the SRAW testing that prevented its success. The discrepancy described above raises concern for the mission-essential capability of SRAW, as it the results do not prove a satisfactory level of reliability. These two criteria (severity and capability) are reasons to put the SRAW into IOT&E, so these issues can be resolved.
A3.
Instead of a deficiency status, an anomaly could have been reported. Using this would ensure further correction without placing the negative connotation of deficiency onto the SRAW test.
B1.
The conclusions I would draw from would be within shots 3, 5 and 7. For shot 3, hangfire occurred thus producing a failed hit, reducing the accuracy and raising concern. However, it is important to note that commonly this can occur when the round is a “dud”, meaning no malfunctioning in the gun was present. Further, the result from shot 5 was a hit, although high winds were present at the target was at 587, the 3rd farthest distance. This would indicate accuracy of the SRAW within unpredictable and realistic conditions, such as high wind. Lastly, shot 7 did not produce a hit at 612 feet, with a 183 target course at 0 kilometers per hour. However, shot 3 indicates a farther distance of 637, with a 210-target course at 10 kilometers per hour, resulting in a hit. The success in shot 3 should particularly highlight the success and accuracy of the SRAW.
B2.
Yes, I agree that there had been too many failures already. The overall accuracy with the test was 70%, leading me to conclude that there needs to be corrections to the SRAW to improve accuracy then tested/evaluated again. Further, the soldier injury during shot 9 leads to the conclusion that after evaluation in what occurred, correction to SRAW may be needed for prevention of reoccurring events.
B3.
The data indicates an issue with the SRAW. Severe dangers were demonstrated within the 10 tests, specifically in shots 4 and 9. Hangfire can result in serious injury, thus its occurrence needs to be taken seriously and looked over to ensure the SRAW is not malfunctioned and that there would not be a high likelihood of this reoccurring. Similarly, the soldier injury in shot 9 produces similar concerns. This event has affected the accomplishment of the SRAW’s capability, with no workaround solution to be known at the time. Lastly, there are discrepancies seen for the SRAW’s accuracy. Shots 3 and 5 were successful under arguably more difficult conditions and succeeded, yet shot 7 was not successful, causing concerns for the mission-essential capability for SRAW and its reliability.
