# Flow Process Grids and Charts in Apparel Industry

In garment manufacturing industry, the production department has three main groups, namely, cutting, sewing and packing. These departments come under the manufacturing section, each section having section in-charges. For example, a pattern master is an in-charge for the cutting unit. They monitor placement of patterns on the fabric lots and cutting the garment parts in an efficient manner. Line supervisors are the in-charges for the sewing section. General maintenance also comes under the production department. Service engineers are the incharges in this department. They are servicing or repairing sewing machines and also cutting machines. In this article I will discuss about flow process charts and grids in garment industry.

Flow Process Charts and Grids:
The flow process chart is a graphical and symbolic representation of the activities performed on the work piece during the operation in Industrial Engineering. Most production managers, engineers and manufacturers are familiar with the use of the flow process charts as a tool for designing production systems and plant layouts. However, one’s ability to use any tool efficiently will vary with the design principles on which the tool is built. A study of flow process charts in various textbooks and technical magazine articles showed that the flow process chart, used in most places, is actually an inadequate tool for production planning purposes. These flow process charts are inadequate because they are diagrams without any time or space scales. Any production blueprint, diagram, or chart must be based on these principles – time and space relationships – if it is to be a worthy engineering tool for calculating production systems and plant layouts. The core of production system efficiency is time, whereas the core of plant layout efficiency is time value based on space relationship plus space values.

If a flow process chart is to be an effective planning device, it should be created with mathematical graph concepts using the grid formation of a y-axis, the ordinate and an x-axis, the abscissa. The y-axis could be the timeline of the apparel production system and plant layout. This timeline represents the time relationships that exist between the work and temporary storage stations in the production flow. The x-axis represents the lateral space relationships among the work and temporary storage stations. The work flows from the base of the graph, the first time level, to the top of the graph, the final time level.

The total production time is equal to the sum of the y time levels. Each time level is equal to the sum of the y time levels. Each time level is equal to the time required to produce a required amount of product units. The production equipment and workers per work station on the graph will be equal to that required to yield the required amount per unit time level. Such a flow process chart, one with a graph grid structure containing ordinate and abscissa values, will be referred to here as a ‘flow process grid’.

Differences between a Flow Process Grid and a Flow Process Chart:
The flow process grid is a dimensional graph of the whole production process of a garment, which measures and depicts the distinct time and space interaction of all factors in the production process such as process stations, inspection stations, temporary storage stations and transport activities, necessary to dispatch a given amount of garments in an intended time and space. The flow process chart is merely a diagram of production sequence without regard to the time and space relationships in the sequence.

The format of the flow process grid must possess the following factors: (1) the spatial relationship necessary between work stations for the best plant layout and (2) the time relationships required among work stations necessary to yield minimum total production time. In order to illustrate these relationships, it is imperative that the grid contains a phrase, word, or symbol for every process inspection station and transportation and storage stations in the production sequence.

Symbols are used on various flow process charts to prefix reports identifying each stage of the apparel production system. This allows one to sort quickly the category of each stage of production. If flow process charts were built on the grid concept, then one could easily identify high rations of transportation and storage in relation to processing. This would enable one to assess a production system very quickly and accurately. It could also highlight the measures necessary to change the system in order to improve the production efficiency. The common process flow symbols used are given in above Table.

Construction of Flow Process Grids:
Since the largest percentage of production labor in apparel manufacturing is most often engaged in the sewing department and since this department usually has the greatest all over production problems of coordinating production between work stations, the principles for making a flow process grid will be developed and illustrated by make of a flow process grid for the sewing production of a simple garment, a men’s T-shirt.

Step 1: List all the sewing operations necessary to produce the garment.

Step 2: Group the operations in levels according to the numerical order in which these operations may be performed to give the quality specifications for the garment.

From these quality specifications, it could be noted that the side seam and underarm seams may be combined into one operation if this is quantitatively better than making it as listed, two separate operations. This permits us to list the operations on the following possible levels of operational sequence:

• Side seams, shoulder seam, collar seam, underarm seam
• Neck seam, sleeve hem, hip hem
• Covering stitch
• Armhole seam

References:

1. Apparel Manufacturing Technology by T. Karthik, P. Ganesan, D. Gopalakrishnan
2. Garment Manufacturing Technology Edited by Rajkishore Nayak and Rajiv Padhye
3. https://en.wikipedia.org/wiki/Flow_process_chart

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