Tuesday, August 28, 2007

Quality Lectures-1

  • Prototype Sample: When- preseason, reason- fit and construction, sketch to garment;size- med; fabric-substitute;time-1-5 days; remarks-resubmissions, more than 1 sample, cost borne by factory, have a counter sample
  • Salesman sample: When-after approval of prototype sample; Reason- for different retail formats; size- all sizes; fabric- no exact color/ print or accessories; remarks- asked by buyer for salesmen, should be charged to buyer if no ordes.
  • Fit sample: after approval of salesman sample; size-med; remarks- ready to orderfabric , reason- to incorporate feedback
  • Size set Sample: One for each size, or jump size set sample; color- any one color; remarks- after this approval for production, can start cutting after this.
  • Sealers sample: for getting fit of all sizes correct; fabric- actual fabric; remarks- approval for production
  • Reproduction Sample or Photoshoot Sample: reason- used for ad. Size: one size, fabric: all colors, actual fabric, for buyer reference only
  • Top of Production Sample: For buyer's reference, medium, randomly picked for production.
  • Shipment Sample: with price ticket, bar code etc.

Remember: All sampling creates a quality history.

- Factors that contribute to variation: Material, equipment, operators, processes, environmentn and inspection systems.

- Variability can be between garments or between garments

- Defects can be critical, major or minor

- Critical Defects are those that affect saleability, usability or performance

- Major Defects are those that affect saleability and may affect performance

- Minor Defects will not affect usability or saleability

  • Critical Zones are defined : For example in A zone, there should not be any critical defect.
  • Inspection loop starts with inspection, detection of defects, feedback of these defects to the personnal concerned, determination of causes of defects, correction of defects and the cycle completes with again inspection.
  • Inspection is defined as the sound judgement on disposition of the product, whether to accept or reject it.
  • Aspects of inspection are purpose, stages, selection of inspectors and how much to inspect
  • Purpose of inspection is to meet specifications, to meet standards and to meet acceptance
  • Stages of inspection are fabric inspection, trim inspection, inline inspection, inprocess inspection and final inspection
  • In trim inspection we inspect sewing threads, zippers and buttons
  • Under sewing threads we inspect construction, sewability, imperfection, finish, color, package density, winding and yardage. Under zippers we inspect dimensions, color, slides, pull tab, slides lock. Under buttons we inspect holes, thickness and color.
  • Under inline inspection we inspect sewing, seam and assembly.
  • Under sewing we inspect needle damage, feed damage, skipped stictches, thread breaks, broken stitches, pucker and pleated seams. Under seam we inspect shape of the sew line, mismatch check, reverse garment part, wrong shade of threads, wrong seam type. Under assemblt we inspect the correct size, parts omitted or incorrectly positioned parts.
  • Under inprocess inspection we inspect spreading, cutting and pressing
  • Under spreading we inspect ply alignment, bowing and splicing.
  • Under cutting we inspect freyed edges, fuzzy edges, ply-to-ply fusion or single edge fusion.
  • Under pressing we inspect burn, water spots, gloss, broken zipper, crease not correct or pocket not smooth.
  • Under Final inspection we inspect collars ( both point, same length) , Button and button holes ( no puckering, even space) Pocket (horizontal top), Hem, yoke, side seam , cuff, finished appearance ( no shade difference). Disadvantage of final inspection is that it is very late, could delay delivery, unsatisfactory products and we need an altogether a complete organisation for alteration. There is also a prefinal inspection when some percentage is left for delivery.
  • Inspection can be done according to place i.e. randomly or after a critical operation eg. front pocket top stitch. Under the latter, not all the pieces are checked, but if there is a bad piece, then all the pieces are checked.
  • Inspection can be pilot run ( After pre production approval, 5 pcs of color, objective is to fine tune the line), Initial ( when x% of pcs. stitched) mid ( when 50% of shipement is stitched)( IN INITIAL AND MID PIECES ARE NOT CHECKED FOR MEASUREMENT) and End of Line ( after 100% production, pcs. checked for measurement)
  • Considerations for selection of inspectors- unbiased, color distinction, communication skills, empathy, ethical)
  • How much to inspect- the options can be no inspection, 100% inspection (never 100% fool proof), Arbitrary sampling ( A certain % of shipment is inspected) or statistical sampling ( Also called acceptance sampling, called AQL ( Acceptable Quality Level) e.g to check for a shipment of 5000 pcs., we see from 3201 to 1000 pieces, we see L, L at 2.5% is 10, means accept till 10 samples are defective in a sample size of 200 pieces, and reject if you get 11. At AQL accept till 14 and reject at 15.

1 comment:

vaibhav bahl said...

the info was really helpful n had hardcore industrial perspective n not bookish. thanx