Test Plan 1
(ME) / Test Plan 2
(IE) / Test Plan 3
(Delphi) / Base Line
Time Requirements
Resources (other than time) Requirements
Sample Size Requirements
Statistical Significance; randomness, independence
Number of Variables
Variability
Ease of Test Performance
Total Rating

Scale 1-5, 1 being the most feasibly, 5 being the least.

Test Plan 1 (ME)

Test Preparation

  1. Delphi will randomly selected 30 heater cores from production throughout the duration of one week.
  2. Measure and record all 6 clinches on each core.
  3. Number all cores 1 through 30.

Test Procedure

  1. Test parts sequentially at 25 psi, 35 psi, 45 psi, 55 psi at room temperature (74º F).

2. Test each parts sequentially at 25 psi, 35 psi, 45 psi, 55 psi at 175º F

3. Test each parts sequentially at 25 psi, 35 psi, 45 psi, 55 psi at 200º F

4. Test each parts sequentially at 25 psi, 35 psi, 45 psi, 55 psi at 225º F

5. Test each parts sequentially at 25 psi, 35 psi, 45 psi, 55 psi at 250º F

Use clay to cover the clinch for outlet pipe. Record leak for inlet clinch. If a leak exceeding 6 sccm is found apply snoop to determine the spot of the leak.

Use clay to cover the clinch for inlet pipe. Record leak for inlet clinch. If a leak exceeding 6 sccm is found apply snoop to determine the spot of the leak.

Example of X = 5 data set

Sequential Data Collection

All parts exposed to each set of conditions at the same time

Time efficient due to minimized change of settings

Temperature 1 / Temperature 2 / Temperature 3 / Temperature 4
Pressure 1 /
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Pressure 2 /
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Pressure 3 /
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Pressure 4 /
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/

Test Plan 2 (IE)

Test Preparation

  1. Classify (good or bad) and number the cores (1,2,3 ….. k)
  2. Measure all clinch gaps for all the cores
  3. Categorize them into one of the three “gap-ranges”
  4. Range 1 (very bad clinches) – core have at least one clinch gap larger than 2.5mm
  5. Range 2 (very good clinches) – core has all clinch gaps smaller than 1.5mm
  6. Range 3 (mediocre clinches) – core doesn’t fall in the either one of the above categories
  7. Perform Leak test at room temperature for all the cores, and separate the cores that have a leak >6cc.

Test Procedure

Testing for cores that fall in Range n ( n = 1,2 or 3)

Temperature 1 / Temperature 2 / Temperature 3 / Temperature 4
Pressure 1 / X11 / X12 / X13 / X14
Pressure 2 / X21 / X22 / X23 / X24
Pressure 3 / X31 / X32 / X33 / X34
Pressure 4 / X41 / X42 / X43 / X44

Xijk stands for number of cores that get exposed to the same pressure/temperature combination.

All X are same, meaning each cell will have same number of cores.

All X are randomly selected from the cores that fall under Range n.

The sequence of testing from cell – to cell and within the cell will be randomized as much as possible.

Expected is that pressure settings will be easy to randomize as well as within cell sequence. Temperatures will be harder to randomize due to outside constraints (time and equipment.)

Illustrate would be expected results if X (number of cores per cell) = 5

For X = 5 (meaning 5 cores per cell), and since n = 3 (meaning 3 gap ranges), and number of cells = 16 total number of cores needed would = 240.

This would give us 3 tables (one for each of the three ranges) such as the one below , with each cell containing a value for leak of core (good/bad, k), with total of 240 data points.

Example of X = 5 data set

Random Data Collection

Each part exposed to only 1 set of conditions

Slow due to large number of changes of the settings and number of data points

Temperature 1 / Temperature 2 / Temperature 3 / Temperature 4
Pressure 1 /
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Pressure 2 /
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Pressure 3 /
/
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Pressure 4 /
/
/
/

Test Plan 3 (Delphi)

Group cores as follows: All cores with all 6 clinch gaps of 2mm or less should be in one group.(There were 14 like this from BAD cores sent)

Randomly chose 21 GOOD cores from your measured Good cores. This will give you 35 cores in the first grouping

All cores with any of the 6 clinch gaps greater than 2 mm will be in the other group. This will give you 35 BAD cores

Test the units at the following temperature and pressure combination - stepping the pressure up from 25-55 psi

If unit leaks in this condition - mark location of leak (clinch area) and measure the leak rate

If the unit does not leak - note that in column and place unit in oven for next temperature range

unit number / Leak Rate (sccm)
Test Pressures/Temp Configuration / Clinch Gap (Y) 0<Y<=2 / Clinch Gap (Y) Y>2
74F / 25 psi
74F / 35 psi
74F / 45 psi
74F / 55 psi
175F / 25 psi
175F / 35 psi
175F / 45 psi
175F / 55 psi
225 F / 25 psi
225 F / 35 psi
225 F / 45 psi
225 F / 55 psi
-40F / 25 psi
-40F / 35 psi
-40F / 45 psi
-40F / 55 psi

Resources Requirements:

Restricted Accessibility to Equipment resulting in significant time constraints: (down to 1 person to do all the testing over couple of weekends)

Testing batches much faster than individual parts (for temperature changes: one part at the time, vs. all parts at once)

Sample Size Requirements:

Relative to Resource accessibility; (Test Plan 2 much bigger sample size requirements (= more time))

Ranges

# of temperature settings, # of pressure settings, # of gap ranges

Relative to resource accessibility; (More variables means bigger sample size, means more time)

Statistical Significance; randomness and independence

Randomness satisfied for sample parts: parts collected randomly from the production line

Randomness in testing restricted with time constraints

Ease of Test Performance

Lack of a pilot study

Variability (exact temperature (and pressure) readings), part handling, single tester variability,

Issues of independence

Memory effects

Isolating affects others than temperature, pressure and gap sizes.