Subject: Apparel Manufacturing. Unit 7: Quality Assurance. Quadrant 1 E-Text

Transcription

1 Subject: Apparel Manufacturing Unit 7: Quality Assurance Quadrant 1 E-Text Learning Objectives The learning objectives of this unit are: Describe the different methods of maintaining quality in the apparel manufacturing industry. Outline the standards and guidelines used in the apparel industry. 7.1 Introduction to Apparel Quality Assurance The word quality has multiple meanings. Two of those meanings are critical, not only to quality planning, but to strategic business planning as well. They are, product performance and freedom from deficiencies '. In the sense of performance, quality refers to the performance features of a product. Such features are decisive regarding product performance and product satisfaction. They compete with each other in the market place. External customers, especially ultimate users, compare competing performances. Their comparisons then become a factor in deciding whose product will be bought. Due to the competition in the market place, a primary goal for product performance is to be equal or superior to the quality of competing products. The word quality also refers to freedom from deficiencies, which takes many forms, such as late deliveries, customer claims and returns, high rate of rework and even cancellation of sales. These are collectively forms of product dissatisfaction. Some deficiencies impact external customers and hence, are a threat to future sales as well as a source of higher costs. Other deficiencies impact only customers and hence, are mainly a source of higher costs. For quality in the sense of freedom from deficiencies, the long-range goal is perfection. Quality is Prevention Constructing solutions to problems before they occur and designing excellence into a product or service. Quality is Customer Satisfaction It is the delight of the ultimate judge of how well products and services measure up. Quality is Productivity

2 Quality is Productivity from employees who receive training, tools and instruction they need to execute their jobs. Quality is Flexibility It is the willingness to change to meet demands. Quality is Efficiency It is doing things quickly and correctly. Quality is Meeting It is a schedule being on time. Quality is a Process It is the process of on-going improvement. Quality is an Investment Because reaping a payoff in the long run, doing it right the first time is less expensive than correcting it later. 7.2 Making Quality Measurable Many companies require regular reports, but take no action to bring about improvements as a result of those reports. A heavy focus is placed on measuring systems and methods, instead of results and possible improvements. Measuring a process without improving it leads to increased costs and lower product quality. 46% of all new product development costs are due to failures, because measurements are not monitored and effective solutions not planned. What gets measured gets managed. Conduct of the quality function depends heavily on the quantification of the product and process characteristics. The process of quantification is called measurement. The measurement results are dependent on the standards being used. Improvement occurs when the measured results are monitored and compared against standards, resulting in actions. The measurement of current performance is essential for continuous quality improvement. What cannot be measured cannot be improved. There is no end to quality improvement processes when results are continuously monitored. Companies measure sales, profits, growth and other parameters to satisfy stakeholders. It is better to monitor the process that provides these results, rather than measure the results alone. Results will follow when input is controlled and the process is monitored. Controlling Quality An effective control system is required to ensure that the whole product stream meets

3 specifications, with only a tolerable amount of exception. Most companies follow the three-tyre system of quality checking. The best results have been found to be achieved with the system which has three component activities, linked by a management report. They are: In-process sampling, 100% examination and quality audit. Quality Assurance Quality assurance refers to the assurance to customers that the product, parts, components and tools contain specified characteristics and is fit for the intended use. In today s competitive industrial world, no business unit can exist for a long time without adhering to quality. Now the assurance of quality is not the responsibility of a senior person or a department only. Only the inspection department or its personnel cannot be held responsible for assurance of quality. It is the responsibility of everybody connected with production, directly or indirectly and each department. The main objectives of quality control are: to identify and mark fabric faults on the fabric, to decide to cut the fabric lot or not, to increase productivity of the cutting department. Quality first products require quality piece goods. Even the most outstanding manufacturing methods cannot compensate for defective materials. You can use these recommendations to help create an aggressive piece goods quality control programme, and eliminate many quality problems before the manufacturing process begins. 7.3 Here are some inspection guidelines: The fabric store should always inspect the fabric as soon as it reaches the facility. Always store the fabric in a clean, moisture free environment. As soon as the fabric arrives, a swatch, (of dimensions as specified by the laboratory), should be submitted to a laboratory, to check the fabric for adherence to fabric performance standards that are required. Many companies prefer to undertake fabric checking while spreading, though at ABC Garments, the fabric is checked beforehand as a separate operation. This is because, while spreading, a spreader is concerned primarily with spreading the fabric and not to inspect the quality of the fabric. Inspection Standards to be followed are: The Four Point System

4 Fabric Meterage to Inspect Roll Size Selection of Rolls Defect Classification Acceptance Point Count The 4-Point System The 4-point system is widely accepted in the textile and garment trade, because it is easy to understand and implement. This system also lays down standards that are proven and acceptable in the garment trade and it is recommended to use the same system while checking fabric. Fabric Meterage to Inspect In this system: At least 10% of the meterage is to be inspected. For a shipment or order of upto 200 meters, it is recommended that inspection should be carried out for100% piece goods. For a shipment between meters, inspection should be done for at least 200 meters or 10%, whichever is greater. Roll Size For better utilisation of fabric, it is suggested that there should not be more than 10-15% of short rolls that is rolls of 20 meters and less in an order. Selection of Rolls At least one roll of each colour that is even if it exceeds 10% of the total meterage, should be selected. In case, more than one roll per colour is to be checked, then select the number in proportion to the number of total rolls per colour received. 7.4 Defect Classification The 4-point system classifies defects as shown in the table. Length of Defect, either length or width Penalty Points

5 3 Inches or less 1 Point Over 3, but not over 6 inches 2 Points Over 6, but not over 9 inches 3 Points Over 9 inches 4 Points Holes and openings 1 inch or less 2 points Over 1 inch 4 Points A maximum of 4 points is charged to one linear meter. Defects less than 1 from the selvedge of the fabric will not be counted. Only major defects are considered. Major Defect A defect that, if conspicuous on the finished product, would cause the item to be a second. Note: When inspecting piece goods prior to cutting, it is necessary to rate questionable defects as major, since the Inspector will not know where the defect may occur on the item. Minor Defect A defect that would not cause the product to be termed a second either because of severity or location. No penalty points are recorded for minor defects. Classification of Major Defects Major Defects are classified as major woven fabric defects, major knitted fabric defects, major dye or printing defects. Acceptance Point Count This method of acceptance uses a projection of total defects based on the number of defects found in an inspection of a sample. Example: The points are calculated on a 100 square meter basis. To calculate the average points/100 square meters for the shipment: Total points counted for all rolls inspected x 39 x 100 Total meters inspected x Cut table width (inches)

6 Up to 40 points per 100 square meters is the acceptable defect rate. 7.5 Quality Control - Spreading and Cutting The objectives of Quality Control Spreading and Cutting are to ensure that all garment parts are cut as per the pattern, decide if garment parts have to be recut, increase productivity of the sewing room. Spreading is not considered an important operation during garment manufacture. It is normally carried out manually, without the supervision of the cutting master and is a critical checkpoint. The post-sewing measurement defects found in a garment can in most cases be attributed to incorrect spreading and cutting. Checking for Defects While spreading, the quality assurance inspector should check the fabric lay for the following defects. In Case of a Marker Always compare the marker with the original pattern. Marker Making Ensure that all parts of a particular garment appear on the marker. Check for the smaller parts [collars/cuffs] and their presence in pairs. Marker Placement To check that the marker is placed on the spread and the edge is parallel to the selvedge of the piece goods. Ensure that all cut pieces are complete. Table Marks Check the table for all table marks. Allow no minus tolerance for splicing [a minimum of one inch of overlap]. Markers Ensure that the marker is not creased, damaged or has overlapped parts. Marker Blueprint Make a random check of some measurements in the marker. Sometimes, while making a blueprint of the marker, unknowingly, the marker gets pulled. This distorts the sizes. Spread Height Ensure that the height of the spread is at least two inches less than the cutting blade knife. In case of knits, ensure that the ply height is stable. Narrow Goods

7 After completion of the spread, check the far edges of the spread to see that all piles extend beyond the marker line. Tension and Creasing Ensure that there is no artificial/excessive tension due to a very tight spread. Also check randomly for any creasing of the fabric. Leaning Check carefully to ensure that one edge of the fabric is square to the table top. Visually inspect to ensure the alignment to the edge with the table top. Count Check the count after completion of spreading, and before cutting. Count all plies at both ends. There should be no tolerance. Checking for Defects Often changes are made to markers to adjust certain production problems. Under no circumstance should such an act be undertaken. In case such a situation arises, all changes should be made in consultation with ABC Garment s merchandisers or quality inspectors. Should there be any changes required in the pattern or marker, a new pattern and marker should be developed. Under no circumstance should changes be made on the same marker. Under no circumstance should any tolerance be allowed in spreading or cutting, as such a defect would lead to accelerated defects while sewing. The Role of the Spreading Inspector The Spreading Inspector should inform the spreading master or cutting masters of the irregularities in the spreading and ensure that corrective steps are taken. In case of re-spreading or re-development of the marker, the Inspector should decide on the date along with the spreader and inform ABC Garment s Quality Inspector. When inspecting: Always try and inspect without disturbing the cut block. This is essential in case the particular piece has to be re-cut. Do not disturb the order of the cut pieces as they have not yet been numbered. Inspection Standard to be Followed These are some of the important inspection standards to be followed: Number of parts to inspect, selection of garment Cut-Parts, defect classification. It is recommended that at least 50% of the garment parts in the marker be inspected. Parts cut on different types of cutting machines are to

8 be taken in the ratio 1:1. This is recommended so that it takes care of both the small and big parts of the garment. For example, the big parts of a Polo shirt are cut on the straight knife and the small parts are cut on the band knife. For the purpose of inspection, the parts chosen for size M would be Fronts, back and Sleeves for the Straight Knife and Placket, Yoke half-moon, Cuffs for the Band Knife. In case all garment parts are cut on one type of cutting machine, the parts selected should be a combination of both the big and small parts. In case, there are a lot of measurement problems observed in the sewing room, it is advisable that all garment parts be checked in the cutting room. In case of particular problems in measurements, such as under or exceeding tolerances, as evident from past records, the quality team should check all the garment parts in the cutting room as per the recommended system. Defect Classification Miscuts Check for miscuts or for the failure of the cutter to split the line. Tolerance is +/- 1/16. Ragged Cutting This is a judgment defect. For certain parts such as pockets and collars, ragged cutting can be a critical problem, whereas, for some parts like the front the defect would be less severe in case the ragged edges are not too severe. Notches The notch location should be checked by placing the pattern over the top ply. Tolerance is +/- 1/8. Check Pattern Compare the pattern to the marker to ensure that the marker was correct. Slant Knife Check the top and last ply for slant knife. This occurs while cutting when the knife blade tilts and results in a difference in sizes throughout the ply height. Measurement Checks Tolerance for: Straight Knife - 3 mm, Band Knife - 2 mm, Dye-cuts - 1 mm. Assess Wastage of Fabric The Quality Inspector should try and assess the wastage of fabric in cutting. In a situation, where excessive wastage is found for example, end wastage, the inspector should make a note and discuss it with the Senior Management.

9 Quality Control - Sewing This system describes how monitoring of quality is an on-going process and not merely a control mechanism. The approach of this method is to be pro-active rather than corrective. The entire system revolves around building quality into the garment and not inspecting quality into the garment. 7.6 Sewing defects begins and ends with the operator. It has been noticed that in most cases, the operator is not aware of what is required from him or her in terms of stitching quality. It is thus imperative that one sealed sample that is a sample as per order; correct fabric and trims, be available and easily accessible to all operators at the shop floor. In case of certain garment parts that require a skilful operation or for a critical operation, the operator should be given a sample of the same for their ready reference. The broad objective of this is that there should never be any legitimate reason for someone not knowing what is happening. 7.7 The 3-Part System The 3-part system is suggested to be used in the sewing room. The components of the 3-part system are: 1. In-process sampling % Inspection 3. Quality Audit In Process Sampling Sampling is more economical and feasible than checking everything. A proper sampling system can give results that are closely representative of the actual situation. Attention can also be focussed on areas where defects are being produced. The objectives of in-process sampling are, maintaining a steady and tight control over all operators, and concentrating attention where poor quality is being produced. The Inspector should be a person not directly responsible for production. The Inspector should have adequate knowledge of the garment being produced in terms of tolerances, stitching details, workmanship quality that is required and manufacturing standards for the garment. The Quality Inspection Sheet should describe: The part or parts they are to stitch together.

10 The workmanship quality pertaining to that particular part for example, a straight seam or a curved one. Any quality problems that might occur at their particular operation. The tolerance pertaining to their sewing operation. This information should be available to the operator at their workstation where it is easy to read. It should be legible, that is it should be neat and if required in the local language. It is the responsibility of the supervisor that each operator understands his or her specification clearly, before production starts. Depending on the results of the check, the whole bundle is accepted as being of satisfactory quality or rejected as being unsatisfactory. The rules, which decide what constitutes a satisfactory or unsatisfactory bundle, are laid down as part of the factory s system. Accepted bundles should proceed to the next operation while the rejected bundles are passed to the supervisor for action. When the operator has been cleared he or she is not checked again, until her name comes up in the normal random sampling procedure. In this way, the Inspector keeps checking a operator whose quality is bad, while still going around the factory checking other operators. Of course, neither the Inspector nor the Supervisor is expected to calmly allow an operator to remain uncleared for quality for long. The supervisor will speak to the operator on the first rejection, and should take urgent action after a second rejection to find out what is wrong, and cure it. An important point of this system is that at no time does the Inspector return the work directly to the operator; only the supervisor returns work for repair. The operator is responsible for that particular section and should review all work that is being returned. The operator will then judge the reason for the defect and take appropriate action, dealing with operator, machine or cut work. The ideal situation is where the supervisor feels that the Inspector is there to help her, by finding quality problems for her before they become serious. This attitude must be introduced from the start when installing a sampling system. The supervisor should be educated to see the Inspector as a helper, an extra pair of eyes, not someone there to create trouble. Unless the supervisors and Inspectors co-operate, the system will not work. Apart from this relationship with the supervisor, the Inspector must be able to understand what is being looked for. The Inspector should also interpret quality specifications and have sufficient confidence in her own judgement to insist that a mistake is a mistake, even when the supervisor says That s not too bad, it can go on. Parameters

11 There are 4 parameters that need to be defined before starting in-process sampling. LOT The collection of garments / parts from where the sample is to be taken. Example: 1 bundle. SAMPLE SIZE The number of garments / parts to be taken for inspection from the lot. Example: 6 garments from one bundle of 25 pieces. ACCEPTANCE NUMBER The number of faulty garments / parts that a sample may have without the entire lot being rejected. Example: 0 out of 6. If there is even 1 defective piece in the sample the entire lot will be rejected. CLEARANCE NUMBER The number of lots that must be accepted in succession to take the operator out of the clearance procedure. Example: 1 lot % Examination It is the process to check all stitched garments and some garment parts in production. 100% examination should be done within the line and at the end of the line. The objective of a 100% inspection is to prevent defective garments from being passed, repair faulty garments and remove the cause of the defects, prevent faulty garments from being passed as perfect. It is likely that after the in-process sampling some faulty garments will be produced. Examination is a stage in the production sequence and is normally regarded as an operation. Most factories examine at the end of the making operations and sometimes at the end of finishing. In other factories, examination is combined with thread trimming. On one hand the trimmer is going over the seams anyway, and you may as well examine at the same time. On the other hand, trimming and examining call for different types of operators, and some operators tend to trim and forget to examine. Whether or not these operations are combined, depends on the personnel of the factory. For economic reasons, there should be as few examination points as possible. On the other hand, for easy repairs, examination points should be placed before any operation which oversees an

12 earlier one. To reconcile these opposing objectives, it should be considered how many defects are actually being produced by each operation, how many are found at the examination point and whether or not these defects will be visible in the finished garment. The usual position for in-line examination points is after a critical component has been made, before attaching it to the main garment. For example, after making a shirt collar. The Inspector should be trained to inspect. This implies that there should be a pre-defined set of actions that is undertaken, to examine each garment or part for visual, measurement and workmanship. Examination tends to be a boring job and any Inspector can become mesmerised after a while and simply not see what is being looked at. To help avoid this, an operation description must be written for this job, detailing how the Inspector should check the garment. The Inspector should be positioned within the line, similar to a sewing operation. The Inspector The Inspector should have a workstation that is adequately large to handle the garment part that is to be checked, as well as the reports, and other work aids that are required to carry out the inspection. The Inspector should have adequate authority not to send a bundle to the next operation in case faults are found. Under no circumstance should an inspector be harassed by the operator to pass on the bundle, just because the production target for the day has to be met. Quality Audit Quality audit is an examination of a small number of garments from the finished stock from sewing. These are taken as representative of the quality that is going to the finishing room. All end-line checkers are audited individually, 4 times a day to ensure control on the checking efficiency of end-line checkers. The objectives of a quality audit are to: Check the other parts of the system, obtain figures which can be compared with figures of in-process sampling, and final inspection, giving comparisons of the effectiveness of the above two systems, look at the garment from the customer s viewpoint and analyze results. The Auditor for the Sewing floor should be a qualified and experienced Quality Controller, and should be able to check a garment thoroughly as per buyer s specifications. The Auditor should himself randomly pick up the garments from each checker s passed pieces. These pieces should

13 not be given to him by the supervisor or any other personnel. He should audit each checker at least 4 times a day, in order to get a representative checking efficiency of the checker. This is the formula for checking the efficiency of a checker. Checking Efficiency = 100% Inspection DHU x % Inspection DHU + Quality Audit DHU Washing and Finishing Audit For the washing or finishing audit, emphasis should be given to areas affected by washing or finishing, such as trimming holes and fraying at the collar due to washing. Quality Audit is an everyday process and should be undertaken without fail. It is recommended that 100% inspection and an audit be carried out either after washing or finishing. In case, the wash process is rigorous or a special wash is being done, it is advisable to check all garments after washing. It is recommended that the garments be slightly ironed and then inspected. The main objective of a 100% inspection is to identify defects that occur after washing. When inspecting, emphasis should be on those areas that are affected by washing, such as button attachment and fraying of collars. The inspection could be combined with thread trimming in case of normal washes. It is recommended that the garments be ironed lightly before inspection. This eases out the creases from the garment and aids the inspectors in identifying defects. Finishing Quality Audit Finishing Quality Audit is an examination of small number of garments passed by the Checkers from finished stock. These are taken as representative of the finished quality going to customers as firsts. It is recommended that Daily Quality Audits are conducted to ensure consistency in quality. It is acceptable to inspect a small number of garments thoroughly. However, under no circumstance should the audit be missed or its results overlooked. The main objectives of the Finishing Quality Audits are, to check the other parts of the system and to obtain figures which can be compared with figures of 100% final inspection. This will give comparisons of the effectiveness of the above system. Finally, it allows an inspection to be done from the customer s viewpoint and to analyze results.

14 The Auditor for the Checkers audit should be a qualified and experienced Quality Controller, and should be able to check a garment thoroughly as per the buyer s specifications. The Auditor should himself randomly pick up the garments from each checker s passed pieces. These pieces should not be given to him by the supervisor or any other personnel. He should do and audit of each checker at least 4 times a day in order to get a representative checking efficiency of the checker. Pre-shipment Quality Audit Quality audit is an examination of small number of garments from finished stock. A quality audit is recommended to be followed after packing of the goods begins. The audit should be conducted daily to ensure that the shipment is of consistent quality. These are taken as representative of the finished quality going to customers as firsts. The main objectives of the Pre-shipment Quality Audit are to check the other parts of the system, obtain figures which can be compared with figures of in-process sampling and final inspection, giving comparisons of the effectiveness of the above two systems, look at the garment from the customer s viewpoint and analyze results. The Auditor for a quality audit should ideally be from the senior management and should try and scrutinize the product from the buyer s point of view. The Auditor should himself randomly pick up the garments to inspect from the day s production. These pieces should not be given to him by the supervisor or any other personnel. Quality Audit Quality Audit is an everyday process and should be undertaken without fail. The following points must be checked for conformity with standard: Carton size. Oversized cartons are not allowed. Carton quality. This includes the carton gross weightas well as net weight. Carton tape. Cartons should not have factory or the vendor s name and address printed on them. Cartons marking should be clearly marked. Un-assorted or broken pre-pack carton numbers packing list must show all the details. Packed quantity. Packing size ratio in a carton. All garments to be packed along with individual polybags. That loose pieces are not packed.

15 The type of fold according to packing instructions. For correct Bar coded ticket with correct placement. o Use scanners to read the bar codes. Size clips that are present, if required. Hang tag positions. Adhesive size strip placement. Garments for workmanship, fit and measurement quality as per the washing audit. 7.9 Conclusion In this unit, you have learnt about In-process sampling, 100% sampling and quality audit. You have also learnt about quality assurance for raw materials, spreading and cutting, sewing, finishing and packing. You have also been given an overview of inspection standards and guidelines for various stages of manufacturing apparel.