FIELD OF THE INVENTION

This invention relates generally to a unique data collection system and method for use in manufacturing operations where the work that is performed is completed on a per piece basis, for example, assembly line type operations. The data collection system and method can be used to track instances and causes of machine and operator down time, raw material quality, attributes of the work environment, and manufacturing equipment performance. The collected data is then used to improve the overall efficiency of the piece work manufacturing operation.

BACKGROUND OF THE INVENTION

In a piece work or an assembly line manufacturing operation, it is common to have a large number of workers (or operators) producing work pieces, e.g., articles of clothing, appliances, or other items that are readily assembled in a piece by piece progression. For example, in the garment industry, a manufacturer would employ a large number of sewing machine operators to piece (sew) together various parts of material to construct articles of clothing (pants, shirts, etc.) in an assembly line procedure. In such a manuf cturing operation, each sewing machine operator would be responsible for sewing the same seam or work piece as part of the garment being assembled. In other words, a single operator may sew nothing but the inseam of a pair for pants during a single working shift. Another operator may only sew on the pockets or belt loops.

In order for a manufacturer to control costs in such an assembly line type of operation, it must have a means to evaluate the efficiency of the workers and the manufacturing operation as a whole, and it must have a way to determine the causes for inefficient operation so corrective action can be taken in a timely fashion.

The art has in the past recognized a need to improve the efficiency of piece work manufacturing operations. For example, an efficiency monitoring device is disclosed in U.S. Patent No. 4,738,132 (Tew) that measures the output of a sewing machine operator on a work versus time profile. This device monitors the speed of the operator's sewing machine, expressed as stitches per unit time, by counting the revolutions of the machine using an infra-red detector. Likewise, the art has recognized the need to test and evaluate sewing threads in order to select the appropriate sewing thread for a given application. However, these thread evaluation methods involved using apparatuses that only simulate the actual commercial environment that the thread is expected to see. For example, U.S. Patent No. 4,899,678 (Simons et al.) discloses a method and apparatus to evaluate sewing threads by simulating conditions normally encountered when performing various fabric seaming operations in the formation of garments. The apparatus is a modified conventional type of sewing machine that allows a continuous test trip of fabric to be subjected to a simulated seaming operation.

None of the earlier known systems or methods have taught or recognized the importance of recording specific and detailed information during the actual manufacturing operation and to use such recorded information to evaluate not only an operator's efficiency, but also the exact causes for an inefficient operation such as raw material quality problems or equipment malfunctions.

SUMMARY OF THE INVENTION

With foregoing in mind, it is an object of this present invention to provide a manufacturer with a system and method to improve the efficiency of the manufacturing processes that involves the repetitive assembly of articles from uniform parts. This invention is especially applicable to an assembly line manufacturing operation or piece work operation, such as garment manufacturing, where each of the workers is responsible for performing a repetitive operating step, such as sewing on a pocket or sewing an inseam, on the garment as it is being assembled. The data collection system and method of this invention allows the manufacturer to determine the number, location and cause of bottlenecks, worker downtime and/or machine or raw material failure. From the data collected and analyzed, the manufacturer can take steps in a timely manner to correct mistakes and improve the efficiency and cost of the manufacturing operation.

The foregoing objects are accomplished using a data collection system for improving the efficiency of a piece work manufacturing operation comprising, (a) a data capture unit capable of receiving input and storing data; (b) a schematic containing data and depicting a work piece; (c) a data transmission unit capable of communicating the data stored in the data capture unit and (d) a data conversion unit capable of analytical manipulation of the data. The above described data collection system can be used in any manufacturing process that uses an assembly line type operation. Any given stage in the assembly line can benefit from the data collection system.

The first step in using the system involves encoding a schematic of the operation that will be worked on or transformed by an operator at a particular stage in the assembly operation. The schematic may be presented on plain paper or other printed format, or as a part of a touch sensitive screen display or otherelectronic medium that can be accessed by a worker at the particular stage of the assembly line operation. If the schematic appears in a printed format then preferably the encoding is performed so that a standard bar code reader can quickly scan specific and predetermined data fields relating to the specific work piece that is being worked on at the particular stage of the assembly line. If, for example, voice recognition technology is used as part of the data capture unit, then the schematic

should be encoded with language or numerals that are easily interpreted by the worker using the data collection system. The schematic should depict or illustrate the particular work piece that the operator will work on. The illustration shown on the schematic does not need to be in full detail, but must sufficiently be representative of the work piece so that special and/or specific locations on the work piece can be designated with encoded data. The schematic can also be encoded with data fields that relate to performance criteria, work piece descriptions and machine and operator identifiers. When the operator encounters a problem with a work piece, raw materials, and/or with the machine or process that is used to transform the work piece, the operator uses a data capture unit, preferably an electronic scanner, to record directly from the schematic information identifying the work piece, the location of the particular stage in the assembly line, operator identifiers, and the cause of the problem encountered, for example, machine breakdown, operator error, work piece defect, raw material problem, etc. The specific information encoded on the schematic is variable and highly dependant on the particular type of work piece and the operation being performed at the particular stage of the assembly. The data capture unit is programmed to automatically record the date, and the time of day, every time the operator uses it to record data from the schematic. Once the operator has entered the appropriate encoded data fields from the schematic, the data is stored electronically in the data capture unit as a discrete event. The operator then returns to the piece work operation until the next occurrence of a problem arises, when the above-described data collection process is repeated.

At the end of the day, or at the conclusion of the operator's shift, the recorded events are communicated from the data capture unit to a data conversion unit, using a data transmission unit. Any means for transmitting the data stored electronically in the data capture unit can be used to communicate the data to the data conversion unit, including a modem, direct hardware connection, infra-red or an intermediary means, such as, a readable tape or magnetic disk. Once the recorded data is communicated to the data conversion unit, programs are run that manipulate the communicated data to provide meaningful outputs of information for use by the manufacturer. Although a great many different types of programs can be run by the data conversion unit, typically such programs involve sorting, statistical

analysis, or generation of easy to read printed outputs of the recorded events. These outputs can include tabulated data or graphical representations of selected recorded data. From the outputs obtained from the data conversion unit supervisors of the assembly line stages can quickly make informed decisions that affects the overall efficiency of the manufacturing process. Likewise, the outputs can be used by raw material manufacturers to improve or modify raw material properties to assist in improving the overall efficiency or quality of the assembly operation.

Other objects and advantages of the invention will become apparent upon the reading of the following detailed description of a preferred embodiment and upon reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic depicting a pant inseam encoded with manufacturing information and other criteria.

FIG. 2 shows a schematic depicting a pocket encoded with manufacturing information and other criteria.

FIG. 3 is a graphical representation of data collected from three sewing machines of a manufacturing process and shows the number of defects versus stage/machine number.

FIG. 4 is a graphical representation of data collected from three sewing machines of a manufacturing process and shows the needle/machine location of defects for each machine.

FIG. 5 is a graphical representation of data collected from three sewing machines of a manufacturing process and shows the type of defects for each machine. FIG. 6 is a graphical representation of data collected from one sewing machine of a manufacturing process and shows the frequency of defects relative to the location on the seam being sewed.

FIG. 7 is a graphical representation of data collected in a side by side comparison of two different yarns being used in three different sewing machines correlated with the number of defects for each yarn.

DESCRIPTION OF A PREFERRED EMBODIMENT

While the invention will be described in connection with a preferred embodiment, it will be understood that the intent is not to limit the invention to that embodiment. On the contrary, the intent is to cover all possible alternatives, within the spirit and scope of the invention as defined by the appended claims.

The ability to evaluate and compare threads and yarns is a goal shared equally by both yarn manufacturers and the end users of those yarns, i.e., the garment manufacturer. In the following description, the word "yarn" is used in its broadest textile sense and also as including all yarn-like structures including, but not limited to, threads, string, cords, twines and ropes. In the garment industry, in particular, there is a strong demand for accurate methods to evaluate the characteristics of sewing threads. The present invention provides both a system and a procedure for such an evaluation using actual manufacturing equipment and operation. This is accomplished by capturing data at a point in time when a sewing machine stops due to either thread failure or machine failure. Two key pieces of data that allows yarn to be critically evaluated are (1) the type of yarn failure and (2) the location of the yarn failure. Recording this data followed by timely analysis allows a manufacturer to find trends which ultimately lead to corrective actions and thus improves the overall efficiency of the manufacturing process. A necessary element of the data collection system is the preparation and use of a schematic depicting the particular work piece that will be worked on and/or manipulated during a given operational stage of an assembly line manufacturing procedure. This work piece may be a pocket, an inseam, a waistband or other sewing operation that is integral to the assembly of the garment. FIGS. 1 and 2 illustrate two schematics, one depicting an inseam and the other a pocket, respectively. In addition to generally illustrating the work piece, the schematics contain blocks of encoded data in the form of bar codes. Each bar coded data block is labeled with a type written description that is clearly legible and understandable by the worker or sewing machine operator. In some cases, multiple schematics may be used to either depict the various attributes of a work piece or to contain additional blocks of encoded data. The form and content of the schematic is highly dependant on the particular work piece being worked on and the

equipment and raw materials being used at the particular stage of the assembly operation.

Another part of this invention is a data capture unit capable of receiving and storing the encoded data from the schematics. Any type of data capture unit can be used to retrieve data from the schematic, for example, computer systems using

( 1 ) a touch sensitive screen that displays the schematic and its associated data fields,

(2) voice recognition technology to interpret and store codes spoken by the operator,

(3) light or laser pointing devices to select coded data fields from the schematic, (4) electronic scanners or (5) other types of "point and shoot" electronic selection devices. A preferred type of data capture unit is the electronic scanner, preferably one that is capable of reading bar code data in an ASCII format. An example of such a bar code reader is described in U.S. Patent No. 4,825,058, which is incorporated herein by reference. It is also preferred that the electronic scanner be hand-held and programmable to accept, recognize and store sufficient data blocks to allow use of the scanner for at least a full day of a manufacturing operation at a given stage of the assembly. The scanner should also be able to accept data identifying a manufacturing location and/or sewing machine operator and to automatically record the date and time of each scanning event. Further, it is desirable that the scanner have a hand-held light pen to facilitate scanning of the bar coded data.

After the data is received and stored in the electronic scanner, it is transmitted using a data transmission unit to a data conversion unit. The data transmission unit can be any electronic device capable of communicating the data stored in the electronic scanner to another physical location. A preferred type of data transmission unit includes one selected from a group consisting of a modem, a hardwire connection, a network connection, an infrared communication device and intermediate means, such as, readable tape or magnetic disk. A most preferred approach is to have the data transmission unit be an integral part of the electronic scanner thus forming a unitary apparatus. For example, if the data transmission unit is a modem, it can be located and connected directly within the electronic scanner and would thus only require a standard analog phone line connector to transmit the stored data. In this way a phone line could be connected directly to the electronic scanner via an RJ l l type connector and the data stored in the scanner

could be communicated via the modem and phone line to a data conversion unit at another physical location.

In order to utilize the information collected during the manufacturing process, it must first be converted into a form useable by the manufacturer. Likewise, the data conversion must be timely so that changes in the manufacturing operation can be quickly implemented. To that end, another integral part of this invention is the data conversion unit. The data conversion unit can be any electronic computing equipment capable of running programs which convert the data originally stored in the electronic scanner and received from the data transmission unit into useable information. In a preferred approach, the data conversion unit is a personal computer programmed to accept, store and convert an ASCII file received from the electronic scanner via the data transmission unit. For example, the ASCII file can first be converted to a Dbase II format and then manipulated by one or more programs to produce an output useable by the manufacturer. Programs can be run to sort, filter, calculate statistical trends and generate written reports and graphics. The exact type of programs run by the data conversion unit is not critical and is highly dependent on the type of manufacturing operation involved and the type and form of useable output desired by the manufacturer. The essential requirement is that the data conversion unit provide a timely analytical treatment of the data collected by the workers so that a manufacturer can detect and correct problems to improve the overall efficiency of the manufacturing process.

EXAMPLE

An experimental test of the data collection system and its method of use was performed at a commercial manufacturing plant producing blue jeans. Using the schematic shown in FIG. 1, depicting an inseam stitch pattern, data was collected for three stages of the assembly line with each stage performing the same sewing operation, but employing a different sewing machine and operator. A portable hand-held Telxon 710 bar code reader with a light pen was used at each stage to record data in an ASCII format by the operator using the schematic shown in FIG. 1. The operator used the schematic each time the sewing operation was halted. The operator used the hand-held scanner to record the reason for the stoppage, whether it was due to the left or right needles and the location on the inseam stitch where the stoppage occurred. If stoppage was due to a maintenance problem, this was recorded as well.

Data collected by the electronic scanner was communicated to a personal computer at a remote location via a built in modem in the scanner using a standard analog phone line. Once the data was received by the personal computer it was converted from the ASCII format to a Dbase III format. Once the data was in Dbase III format various programs were run using the personal computer to generate graphical outputs that summarized and analyzed the performance of the three stages of operation. Examples of the type of graphical outputs generated are illustrated in Figures 3-7.

The graphical data presented in FIGS. 3 - 5 illustrate the data collected for the three different manufacturing stages, each performing the same sewing operation. FIG. 3 graphical displays the total number of defects for each stage (identified as Sewing Machine #). As indicated, Sewing Machine #1696531 had the least number of recorded defects even though the data was collected for a longer period of time. FIG. 4 indicates the relative number of defects occurring in the Right Needle versus the Left Needle for each Sewing Machine #. FIG. 5 identifies the causes of the defects for each stage, i.e., whether the stoppage of operation was due to a skip stitch, thread breakage, or a raw edge. FIG. 6 presents data for only one stage (Sewing Machine #299209) and shows the frequency of defects per the

predefined locations along the inseam stitch. These predetermined locations correspond to the bar coded data in FIG. 1 having the numerical labels from 01 - 09.

Finally, a comparison of two different yarns, in this case sewing threads, manufactured by two different suppliers is graphically presented in FIG 7. On average, Yarn # 1 out-performed Yarn #2 as indicated by the number of inseams completed per recorded defect.

As indicated from the above-described example, the data collection system of this invention is capable of obtaining a wealth of information that a manufacturer can use to monitor and improve the efficiency of a piece work operation. It will be recognized that modifications and variations of this invention will occur to those skilled in the art, and it is intended that all such modifications and verifications be included within the scope of the claims.