THE ART OF FLAWLESS SEWING: Mastering Inline Quality Control In Sewing Operations/Machines.

Introduction:

?Quality control is an important and crucial aspect of garment manufacturing units, particularly when it comes to inline quality control in sewing operations. This essential element of garment manufacturing is often overlooked, despite its significance. As there are few resources available on this topic, I have decided to write about it using my experience and knowledge gained over the past two decades in this field.

?Typically, when I ask Quality Controllers (QCs) in the sewing lines about performing inline inspection, their response is to check each sewing operation/machine and search for defects[1] like skip stitches, oil stains, stitch jams, run-off stitches, pleats, puckered seams, stitches per inch, needle holes, trims, accessories, open seams, etc. If any defects are found, the QCs instruct the operator/supervisor to make the necessary corrections before continuing with the sewing process.

?While the Quality Controllers' responses are usually accurate and consistent with each other, they tend to struggle in providing a consistent answer when asked about what to inspect in each operation/machine on the sewing line. If all Quality Controllers in a manufacturing facility had a uniform understanding of how to perform and what to inspect at each sewing operation/machine, they would be able to provide accurate and consistent answers.

When we examine their responses more closely, some of the answers are not relevant and do not provide accurate information, while most of them are on-point and concise. For example,

Fabric: While it's true that every QC and checker in the factory is capable of inspecting fabric quality, it raises the question of why the QC in the sewing line specifically needs to check this aspect. Additionally, if the QC in the sewing line is responsible for checking fabric, what is the role of the quality control checker in cut panel audit?

Trims and accessories: Have you ever asked an inline QC about trims and accessories? Surprisingly, more than 60% of them do not know the difference between these two. While it's not necessary to know the difference to check this aspect in the sewing line, it highlights the level of training and understanding they have. Trims can be checked during sewing as they are meant to be sewn/attached on the product, but accessories cannot be validated as they are added in the finishing department to facilitate the sales.

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[1] I would like to emphasize an important point before proceeding. Searching for defects is not the appropriate approach to find defects when examining a semi-finished or finished garment. If you wish to learn how to identify defects efficiently and easily during garment inspection, I recommend reading my previous article, "Beyond Defect Detection: The True Purpose of Garment Inspection " which provides a clear explanation of the process.

What is Inline Quality Control and what is its purpose?

The process of inline quality control is a quality assurance technique that aims to evaluate the accuracy of work done by either the operator or machine in every sewing operation on the production line before the garment is completely sewn. The primary goal of inline sewing quality control is to detect and address issues in each sewing operation to eliminate recurring problems.

It's crucial to remember that preparatory tasks like ironing curved corner pockets, ironing cuffs, marking pocket and snap fastener placements, and marking for buttons and buttonholes, which aid subsequent sewing operations, etc. should also be considered part of the sewing line's work and examined for perfection.

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The Importance of Inline Quality Control in Sewing Operations

?●?????It helps to identify defects or issues early in the production process, which can be corrected before the garment is finished.

●?????It can effectively pinpoint both the operator and the machine responsible for recurring deviations in the sewing process.

●?????It helps to reduce the number of rejected garments, which can result in achieving quantity requirements and cost savings for the manufacturer.

●?????It can improve production efficiency by catching and addressing problems before they become larger issues that require more time and resources to fix.

●?????It ensures that the finished product meets the customer's sewing requirements and trims’ specifications.

●?????It helps to build customer trust and confidence in the manufacturer's product, which can lead to increased sales and repeated business orders.

Let's examine what really happens during sewing operations.

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Understanding the Process of Sewing Operations

The actual physical construction of a garment takes place during the sewing operations. This process involves stitching together the different components of the garment, such as the sleeves, front and back panels, pockets, plackets, yoke, labels, buttons and collar (in case of a shirt). The sewing operations require a combination of skilled labor and advanced machines to ensure that the garments are made correctly and to the required specifications.

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The Significance of Skilled Labor in the Workplace

?During sewing operations, each garment component must be aligned and positioned correctly to ensure that the stitching is accurate and consistent. The seam allowance, or the distance between the stitching and the edge of the fabric, must also be precise to ensure the durability and appearance of the garment. Skilled workers have a thorough understanding of sewing techniques and garment construction, as well as knowledge of different fabrics and their properties, to ensure that the garments are made to the highest standards.

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The Importance of Efficient Machinery in Sewing Production Lines

?Well-functioning machines are extremely vital in a sewing production line as they can significantly impact the quality and efficiency of the production process. Any malfunction or breakdown in a machine can lead to delays, defects, and even halt the entire production line, resulting in a loss of time and money. Therefore, it's crucial to ensure that all machines are regularly maintained, repaired, and replaced as necessary to minimize downtime and maintain optimal production quality.

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Proven Methods for Inline Inspection in Sewing Lines

?Numerous inline inspection methods are commonly followed in garment manufacturing factories, but only a couple have been shown to be highly effective in minimizing rework rates and achieving optimal quality. The Statistical Process Control (SPC) and Traffic Light System are two such methods. Please do not assume that I will suggest you to adopt any of these methods to become competent in inline quality control. I am merely providing an explanation of these methods for your understanding. We will explore a new and practical quality control approach for sewing lines at a later time.

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The Statistical Process Control (SPC)

Statistical Process Control (SPC) is a proven method to minimize discrepancies in everyday processes with the aid of fundamental tools, including Cause-and-effect diagrams, Check sheets, Control charts, Histograms, Pareto charts, Scatter diagrams, and Stratification.

?This technique is highly effective in analyzing, controlling, and managing processes by identifying and eliminating special causes of deviation, such as the use of improper raw materials, machine faults, operator errors, deviations in measurements, and other factors that can lead to defects in the final product. However, the implementation and usage of this process in the garment manufacturing industry are still relatively low due to the need for extensive data entry and tracking, as well as a well-organized team.

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Traffic Light System

It is primarily a visual approach to identifying, correcting and flagging quality concerns in a sewing line. The system adopts Green, Yellow, and Red color codes to create a visually appealing indicator for specific operations/machines. The method involves inspecting five to ten garments in each operation, and operations with no defects are marked with a green flag. If one defect is found, a yellow flag is used, while two or more defects mandate a red flag.

One of the greatest benefits of this system is its ability to monitor the performance of every operation and machine. The following example is presented in a weekly format, but it can be expanded to encompass monthly tracking simply by adjusting the dates. It is unfortunate that this effective approach is used and implemented to a limited extent.

Limitations of Current Inspection Methods and Tools for Sewing Operations

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Next time you visit a garment factory, just ask them for their inline quality control report on the sewing floor. You are likely to receive a report that resembles one of the following examples.

If you review this report closely, you can realize that this is not actually an Inline quality control report but it is a report generated by checking the finished products at the end of the sewing line. So technically it must be called "End-Of-The Line Inspection Report”. The QCs checks random garments at the end of the sewing lines. Based on the defects observed and the measurement deviations found, they will ask the operator/incharge to correct the same. This approach only fixes issues but does not guarantee achieving the Right First Time (RFT) quality.

Example 1:

Typically, this report is generated at the end of the sewing line or on the finishing floor. It features the date and order details at the top, required measurements and/or actual findings in the middle, and a list of defects with corresponding comments on how to address them at the bottom. The report is then signed by the QC, quality manager, production manager, and other relevant personnel.

Example 2:

?We can consider this as an inline inspection report that is suitable for use in sewing lines but still it lacks crucial check points.

This inline inspection report is highly useful and is typically recorded at every operation/machine on the sewing line. The report begins with the date and order details at the top, followed by operation or operator-wise checking and details of any detected defects in the middle section. The bottom section contains comments and recommendations for improvement. Finally, the report is signed by the QC, quality manager, production manager, and other relevant personnel.

Example 3:

?This is again a report used to inspect finished garments and document the results of the audit. This report follows a similar format with order details and current status of the order located at the top, predefined defects list and defects identified in the middle, and comments situated at the bottom. The QC responsible for conducting the audit, the line supervisor, production manager, and quality manager then sign the report.

Example 4:

Once again, we can consider this as an inline inspection report that is suitable for use in sewing lines but still this lacks focus as it indirectly encourages the search for the pre-defined defects in every operation.

This report adheres to a comparable structure where the order details are located at the top. The middle section contains predefined sewing operations, hourly findings, and a list of defects with predetermined codes for both top and bottom category products. Comments are situated at the bottom of the report. Subsequently, the QC in charge of the audit, the line supervisor, production manager, and quality manager signed the report.

There may be various inline inspection reports used in different factories, but most of them can be categorized into one of the four given examples with some variations. It's crucial to note that only a small fraction of these reports are appropriate for use as an inline inspection report in sewing lines. The majority of these formats do not offer enough space for a QC to document the checks conducted at each sewing operation or machine. If you're wondering what the appropriate format for inline inspection is, let's explore that further to find the answer.

Addressing the Gap in Sewing Operation Documentation

It is important to mention that most of the factories have good inspection documentation/reports in every department except the sewing line quality control report.

For instance, during a visit to the fabric department, we can easily notice the following activities and documents/reports for the same:

●?????Inspection of incoming fabric,

●?????creation of shade bands to assess uniformity of the color and segregating different shades,

●?????fabric relaxation,

●?????Roll wise dimension stability summary for grouping to make marker & cutting plan etc..

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Similarly, when visiting the Cutting department, it's ideal to see the following activities and reports:

●?????Lay spreading control,

●?????marker inspection,

●?????cut panel audit to verify quality of cutting, notches against the marker/pattern,

●?????cut component checking for fabric flaws,

●?????fusing quality control etc..

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When comparing the activities and reports in each department such as Fabric, Cutting and Finishing, you will find that the reports generated are based on the actual activities being followed in that particular department. The purpose of having these reports for each activity is to document and analyze the findings for the purpose of improvement. However, it is surprising that when visiting the sewing floor, the only and crucial activity is the creation of a garment using different seam constructions, but there are no reports that help document the checks performed during the sewing operation.

In summary, it is evident that the sewing quality control process lacks both focus and documentation. Therefore, it is crucial to develop a comprehensive report that can effectively document sewing control activities. Prior to examining the report format, it is necessary to understand how to check and what to look for in each sewing operation or machine.

How to perform inline quality control in sewing lines?

Whenever a sewing operation/machine is used, a seam is produced. Therefore, the main objective of the quality control process in sewing should be inspecting the seam that was created. To conduct a thorough seam inspection, it is crucial to take into account the following significant factors:

●?????Firstly, the seam should be completely flat

●?????Secondly, it is important to ensure that the stitching and seam allowances are consistent.

●?????Lastly, it is crucial to ensure that the stitch density and thread tension are uniform.

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Before diving into the details, it's important to understand the following terms:

●?????Seam: the line that joins two or more pieces of fabric together through stitching by hand or a sewing machine.

●?????Seam Margin or Allowance: the space between the edge of the fabric and the line of stitching forming the seam.

●?????Stitch Margin or Gauge: the distance between the needles used to make the seam, in case of multiple needles involved.

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Firstly, the seam should be completely flat.

This can be determined by examining the seam and ensuring that it is perfectly flat. If the seam is not flat, you may notice that it appears stretched, wavy, puckered, pleated, frayed edges or shaped off. In case of elasticated gathering or pleated style requirements, look for even flat and evenly distributed gathering, as per the requirement. Refer to the images for details.

Secondly, it is important to ensure that the stitch and seam margins are consistent.

To check this, look for the perfect gauge between stitches, the correct placement of stitches, and appropriate hem/seam allowances. If there are any issues, you may come across run-off stitches, uneven seam/hem width, irregular stitching allowances, or incorrect placement of stitching. Refer to the images for details.

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Lastly, it is crucial to ensure that the stitch density and thread tension are uniform.

To check this, look for uniform stitches per inch (SPI) and appropriate thread tension throughout the entire seam. If there are any issues, you may encounter skip stitches, broken stitches, missing stitches, joint stitches, irregular stitches, open seams, or thread tension that is too loose or too tight.

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?Note: These guidelines are relevant for all types of construction, such as single needle, twin needles, or three needles, as well as for all kinds of sewing machines, including lock stitch, chain stitch, and overlocking seam machines, bar tack, buttonhole etc...

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Hope it is understood that to ensure the quality of a seam, it's important to examine these key aspects in every sewing operation or machine used in the sewing line. With this understanding, the inline inspection report for sewing operations should be formatted as follows, with the scope of recording these checks in each operation.

Instructions: Examine a minimum of seven units in each sewing operation or machine. Check for a flat seam, consistent seam, stitch margin, even stitches per inch (SPI), and optimal thread tension. For overlocking seam, assess the sharpness of the blades. Use a tick to indicate if the criteria is met, otherwise use a cross mark for Seam and Margin. For SPI, count the number of stitches per inch for each seam and record the value in the report.

Why Achieving Results is Challenging Despite Available Resources: A Closer Look

?After learning how to perform inline inspections and what to look for in each sewing operation/machine, as well as how to generate audit reports, it's essential to understand that merely providing this report to QCs and expecting them to resolve all the issues that arise in each operation is not sufficient. While these checks undoubtedly help in identifying issues, if the QCs don't have the necessary training to address them and find a solution, the checks alone are not effective.

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●?????It's essential to keep in mind that identifying a problem is just the first step in quality control.

●?????The next step is to identify the root cause of the issue and develop a solution.

●?????The final step involves implementing and consistently monitoring the solution to ensure it's effective.

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Common QC Mistakes in Sewing Operations Inspection

QC Instructs and pushes the sewing operator for corrective actions.

If there is puckering in the seam, the QC may advise the operator to adjust the pressure foot.

Similarly, if the seam is stretched, the operator is advised not to stretch the fabric while feeding.

In case of skip stitches, the QC may suggest checking the thread tension and passage.

If the SPI is more or less than the desired value, the operator is advised to adjust the SPI and proceed. Finally, if the looper thread tension is too tight compared to the needle thread tension, the operator is advised to loosen the looper thread tension.

The approach of allowing the QC and Operator to adjust all machine settings, such as pressure foot, thread tension, and SPI, is deeply flawed. This approach does not facilitate the identification of solutions to problems and instead creates further difficulties for the maintenance department. After all, if the QC and Operator are capable of making all necessary adjustments, what is the purpose of the maintenance department and its team members in every factory?

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QC Rushes to the Next Operation Without Verifying Corrective Action First.

?Another common mistake made by the QC team in many factories is not waiting to observe how the maintenance staff carries out the corrective action on the operation or machine. Instead, they immediately move on to the next operation once the maintenance staff begins working on the issue. It is important for the QC team to oversee the corrective action and verify that it has been implemented effectively before moving on to the next operation.

Missing Opportunity to Learn Valuable Sewing Skills for Various Issues.

It's unfortunate that the QC team seems to be unaware of the immense potential for real-life learning opportunities when it comes to handling issues that arise in various sewing operations and machines. The maintenance staff always carefully assesses both the machine and the operator handling before making recommendations on which one to address. I've experienced this many times in my profession, where I initially thought the issue was with the machine, but the maintenance staff solved it simply by improving the operator handling. By closely observing the activities of the maintenance staff, the QC team could learn how to thoroughly analyze both the machine and the operator handling before making any conclusions.

Implementing Inline Quality Control in Sewing Operations: A Simple Process for Ensuring High-Quality Results

To ensure high-quality sewing operations, implementing inline quality control can be a straightforward process as long as the QC team understands the steps involved. These steps include:

1. Examining an operation to identify any deviations.
2. Recording findings in a report.
3. Contacting maintenance staff/production incharge to examine the deviation, machine, and operator handling, and suggest or make necessary corrective actions.
4. Verifying if the operation is now perfect or not.
5. Allowing the operator to proceed with further sewing if the operation is deemed perfect, and urging the maintenance staff to improve it further if it is not.
6. Verifying the operation once again to ensure it is perfect.
7. Moving on to the next operation or machine.

By following this process, the QC team can ensure that any deviations or issues are promptly resolved by the maintenance staff, and that sewing operations are of the highest quality. Although this process may seem easy and straightforward, real-life scenarios can often present challenges.

Challenges in Real-life scenario

1. Progress made, but what is the goal?

?An example of a real-life scenario could be when the QC team identifies a stretched and wavy side seam. They record the deviation in the report and request the maintenance staff to find a solution. After making the necessary corrective actions, the maintenance staff proposes a side seam that is an improvement over the previous one, but still slightly stretched and wavy.

At this point, even many of the experienced QCs may falter by comparing the corrected seam with the previous one and overlooking minor deviations. However, this approach is flawed. The QC team should stick to their requirements and evaluate each seam based on its individual merit. In this case, the primary requirement is that the seam must be flat, regardless of how it compares to previous seams.

2. Made everything appear alike, but is that what's needed?

Another example from a real-life scenario could be when the QC team identifies uneven thread tension in a three needles chain top stitching operation. One looper thread has optimal tension, while the other two are very tight. The maintenance staff adjusts the optimal looper thread to make the appearance of all three looper threads look similar. However, this adjustment results in all three looper threads being very tight in tension.

To make the correction easier, the maintenance staff may be tempted to tighten only one looper thread instead of adjusting the other two. However, if the QC team's focus is on achieving optimal thread tension, they will not accept this solution. They need all looper threads to have optimal tension, even if it takes more effort to adjust the tighter ones.

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3. Perfection attained, but who accomplished it?

A third example from a real-life scenario could be when the QC team identifies a stretched seam and requests the maintenance staff to correct it. The maintenance staff checks the machine and the operator and claims that the machine setting is perfect, instructing the operator to handle it properly. The operator makes another seam, but unfortunately, there is no improvement.

To prove that the machine setting is correct, the maintenance staff sews 4-5 garments and shows them to the QC team, which appears to be flat. However, many QC teams may overlook the fact that the maintenance staff is not responsible for sewing throughout the day - it is the operator who will be sewing the rest of the garments. Therefore, the QC team must wait and verify the operator's work until the seam is perfect and flat.

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4. Reasons exist, but are they valid for imperfection?

The Quality Control (QC) team discovered an operation with an improper seam margin and notified the maintenance staff to address the issue. The maintenance staff assessed the machine and the operator and determined that the machine settings were correct but the operator made an error. The operator attempted the seam again but it still did not meet the necessary standards. At this point, the production incharge intervened and explained that the regular operator responsible for this task was absent, and a new operator had been assigned to perform the job, assuring that the operation would be perfected after some time.

However, the QC team should not accept this explanation and move on to the next operation. It is the responsibility of the production team to assign a skilled operator for each operation, regardless of the nearing delivery or shortage of manpower availability. These factors should never be an excuse for poor workmanship.

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Other Real-life scenarios of production team sabotaging QC processes

Here are some typical things that production and maintenance teams might say to explain, justify or excuse certain situations in real-life.

●?????Keeping slight gathering during production to avoid Out of Tolerance (OOT) measurements at this measurement position.

●?????This product undergoes washing treatment after sewing, which will cause it to shrink, so any waviness in the seams will not be present in the final product after treatment.

●?????The fabric used in this product has stretching properties, so this is the best possible outcome.

●?????Other customers are accepting deviations up to this level, so it should be acceptable.

●?????The fabric is very thin and delicate, making it challenging to handle as intended.

●?????We are regularly checking and changing the blades to ensure the best possible cut.

●?????The approved reference sample has similar deviations and has been accepted by the customer without comments.

●?????We have been making shipments with similar deviations for years, and the customer has not complained.

●?????This is the best possible stitch per inch (SPI) achievable for this seam. If we increase it, the machine will likely get stuck.

●?????The slight puckering in seams can become flat during ironing, etc..

Always remember, the production team's primary concern is productivity and meeting delivery deadlines, while quality is secondary. However, for the Quality department, quality is the priority, and they prioritize it over productivity. This may lead the production team to employ various tactics to deceive the QC team and meet their delivery goals. As a result, the QC team must be thorough and vigilant in their verification process to ensure that the production meets the required quality standards.

By doing so, the QC team indirectly supports the production team in achieving their goals by minimizing reworks and rejections, resulting in perfect quality, meeting delivery deadlines, and shipping out the ordered quantity.

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I hope you found this article on implementing inline quality control in sewing operations helpful. By following the steps outlined in the process and remaining vigilant in the face of real-life scenarios, QC teams can ensure that production meets the highest quality standards. Remember, effective communication and collaboration with the production/maintenance staff are critical to achieving these goals. With dedication and attention to detail, we can all contribute to delivering high-quality finished products that meet and exceed customer expectations.