Fabric width is stable near 153 cm, but the agreed range is 148–152 cm. Which action addresses the source of the mismatch?
A Stop measuring width
B Recenter the process mean
C Increase random selection only
D Widen control limits alone
Answer: B. Recenter the process mean. A stable process can still make unacceptable output. Adjust its average toward the specification target.
Two lots show equal defect counts, but one inspected area is twice the other. Which effective comparison should be made?
A Unscaled counts alone
B Inspector arrival times
C Roll width labels only
D Defects per unit area
Answer: D. Defects per unit area. Counting defects relative to inspected area gives comparable defect densities.
In one Pareto tally, seam faults number 35, shade faults 20 and sizing faults 15. What percentage of all 70 faults are seam faults?
A 28.6%
B 71.4%
C 50.0%
D 35.0%
Answer: C. 50.0%. Divide the seam total of 35 by the overall 70.
Find the arithmetic mean for four areal density readings of 148, 154, 152 and 146 g/m².
A 152 g/m²
B 150 g/m²
C 148 g/m²
D 151 g/m²
Answer: B. 150 g/m². The sum is 600 g/m². Divide by four.
On every reference check a gauge reads 1 mm high. Which error does this show?
A Systematic bias
B Process improvement
C Random variation only
D Greater textile variability
Answer: A. Systematic bias. The consistent offset from a reference is a systematic measurement error.
Eighty garments are inspected. Ten garments contain one or more defects, with 16 individual defects in total. Find defects per hundred inspected units.
A 16
B 12.5
C 80
D 20
Answer: D. 20. Divide the 16 defects by 80 inspected units and multiply by 100.
When a measured defect category is rare but severe, why might the largest Pareto count fail to set the first priority?
A Counts omit defect severity
B All defects have equal impact
C Pareto charts show fabric size
D Counts always track severity
Answer: A. Counts omit defect severity. Frequency rankings should be considered with consequence. A less frequent severe defect may need faster action.
Measured finished widths are 147.8, 148.6, 150.0, 151.3 and 152.5 cm. How many satisfy inclusive limits of 148–152 cm?
A Five
B Four
C Three
D Two
Answer: C. Three. 148.6, 150.0 and 151.3 cm fall inside the limits. The lowest and highest readings do not.
From 120 items, 12 are nonconforming. What is the probability of selecting one nonconforming item in a random draw?
A 0.10
B 0.12
C 0.01
D 0.90
Answer: A. 0.10. The first random draw has probability 12/120.
Using a point-based scheme, 18 points are recorded on 45 m². How many points are there per 100 m²?
A 40
B 18
C 81
D 25
Answer: A. 40. Normalise the 18 points to 100 m²: 18/45 × 100.
Repairs reduce the number of units failing final inspection, but the line still generates the same number of defects initially. Which measure reveals that production has not improved at first pass?
A Final packed count only
B Total cutting speed
C Average fabric width
D First-pass yield
Answer: D. First-pass yield. First-pass yield counts initial passes before any repairs and therefore reveals whether defects are being prevented.
Near a knit machine, a vertical streak returns at the same wale after each restart. Which evidence could help locate the fault?
A Ignore the streak positions
B Map it to needle position
C Change every yarn lot
D Average all fabric shades
Answer: B. Map it to needle position. A persistent defect at the same wale points to a recurring machine position, such as a damaged needle.
Take five width measurements every hour from fabric produced close together in time, rather than mixing several shifts into one subgroup. Why?
A Increase the sampling interval
B Represent short-term process variation
C Erase all width changes
D Make sample means identical
Answer: B. Represent short-term process variation. Keeping subgroup conditions similar better reflects short-term variation and helps detect changes between subgroups.
Out of 240 units sampled from a shipment, 12 are nonconforming. What proportion failed?
A 12.0%
B 2.0%
C 5.0%
D 20.0%
Answer: C. 5.0%. The fraction is 12/240 = 0.05.
Under the stated double sampling plan, two faulty items in the first sample require a second sample. Exactly two are found. What should the inspector do?
A Take the planned second sample
B Automatically reject the lot
C Increase the acceptance number
D Automatically accept the lot
Answer: A. Take the planned second sample. The first result falls in the continuation region. Follow the stated rule and inspect the second sample.
Strength readings in one subgroup are 40, 38, 42, 39 and 41 N. What should be plotted on an R chart?
A 40 N
B 4 N
C 2 N
D 42 N
Answer: B. 4 N. The subgroup range is 42 − 38 = 4 N.
Width varies with a visible position-dependent pattern across the same fabric roll. Which reporting practice helps investigation?
A Keep only the grand mean
B Randomly swap location labels
C Discard all edge readings
D Retain measurement locations
Answer: D. Retain measurement locations. Recording where each reading came from helps distinguish widthwise effects from overall variation.
Three sampled rolls score 10, 18 and 22 points over inspected areas of 40, 60 and 100 m² respectively. What is the combined point rate per 100 m²?
A 75 points
B 50 points
C 25 points
D 16.7 points
Answer: C. 25 points. The inspection covers 200 m² and records 50 points. Normalized to 100 m², that is 25 points.
Rolls from three suppliers are sampled in proportion to each supplier’s share of the lot. Which sampling design is used?
A Stratified sampling
B Only one random cluster
C Inspecting every item
D Convenience sampling
Answer: A. Stratified sampling. Supplier groups are strata. Sampling within each group preserves their representation.
Without changing within-group variability, subgroup means shift upward after a chemical recipe change. Which chart generally shows that upward shift most directly?
A Check sheet totals only
B Defect Pareto chart
C R chart only
D X-bar chart
Answer: D. X-bar chart. The X-bar chart tracks subgroup means. An R chart primarily tracks spread.
Shrinkage readings in ascending order are 1%, 2%, 2%, 3% and 6%. If only the largest becomes 9%, which statistic stays unchanged?
A Mean
B Range
C Median
D Maximum
Answer: C. Median. The middle value remains 2%. Changing the largest value changes the maximum, range and mean.
Inspectors disagree on whether minor marks qualify as faults. Which improvement addresses agreement directly?
A Remove all acceptance rules
B Average the cloth width
C Define defect examples jointly
D Raise loom speed
Answer: C. Define defect examples jointly. Common defect definitions and reference examples improve agreement when classifying observations.
Systematic inspection picks every 20th garment, and a defect also repeats every 20 garments. What problem can arise?
A It removes all bias automatically
B The method inspects every unit
C It makes faults appear randomly
D Sampling may miss the cycle
Answer: D. Sampling may miss the cycle. A fixed sampling interval can repeatedly hit the same position in a systematic defect cycle.
Defect rate falls from 8 to 6 per hundred units. What is the relative reduction?
A 2%
B 75%
C 33.3%
D 25%
Answer: D. 25%. The drop of two defects per hundred is 2/8 of the starting rate.
First-piece inspection finds pocket placement changed after a guide was replaced. What should the team check?
A All rolls from last year
B Guide setting against specification
C Packaging carton colour
D Only total weekly output
Answer: B. Guide setting against specification. The timing of the change suggests checking the new guide location against the required position.