1.1. Introduction
Apparel manufacturing is labour intensive, which is characterised by low fixed capital investment; a wide range of product designs and hence input materials; variable production volumes; high competitiveness and often high demand on product quality (Scott, 2006; Hassler, 2003; Forza and Vinelli, 2000). Although the manufacturing process is associated mainly with apparel and household linens, it is also used in a variety of industries and crafts such as upholstery, shoe-making, sail-making, book-binding and the production of varieties of sporting goods. Sewing is the fundamental process, with ramifications into a variety of textile arts and crafts, including tapestry, quilting, embroidery, appliqué and patchwork.
The apparel-manufacturing process evolved as an art and underwent several technical changes. The technological advancements in the apparel industry include the use of computerised equipment (especially in design, pattern-making and cutting), 3D scanning technology, automation and robotics, integration of wearable technology and advanced material transport systems (Bailey, 1993; Forza and Vinelli, 2000). Another important development involves the increasing use of robotics to transport components and materials within the plant, which helps in improving production efficiency. However, the apparel industry â especially sewing technology â has remained significantly less automated compared to many other manufacturing industries.
There are wide varieties of clothing types that the apparel manufacturers have to handle, which can be broadly divided into two categories: outer clothing and inner clothing. Outer clothing includes work-wear and uniforms, leisure wear and sportswear (e.g. suits, pants, dresses, ladies' suits, blouses, blazers, jackets, cardigans, pullovers, coats, sports jackets, skirts, shirts short- or long-sleeved, ties, jeans, shorts, T-shirts, polo shirts, sports shirts, tracksuits, bathing shorts, bathing suits and bikinis). The underclothing (underwear) includes jersey goods and lingerie (e.g. underpants, undershirts, briefs, socks, stockings and pantyhose). These products are manufactured in a wide range of design and style variations, which increases the complexity of the manufacturing process.
1.1.1. Sewing: the art of joining materials
Sewing can be defined as the art and craft of fastening objects by stitches produced with a needle and a thread. It is considered one of the oldest textile arts, and started in the Palaeolithic Age before the invention of spinning yarn or weaving fabric (Angier, 1999). During the Palaeolithic Age, animal hides were stitched together by sewing and used for clothing and shelter. Tools such as needles, pins and pin-cushions were used as sewing aids in the bridal wear of many European brides from the Middle Ages to the seventeenth century. It is also believed that Stone Age people across Asia and Europe used to produce clothing items from fur and skin by joining them with needles such as bone, antler or ivory and threads prepared from various animal body parts including sinew, catgut and veins.
In the American plains and Canadian prairies, the indigenous peoples had adopted sophisticated sewing practices to assemble tipi shelters. In Africa, sewn baskets were produced by the combination of sewing and weaving of plant leaves. For example, the baskets prepared by Zulu weavers used thin strips of palm leaves as âthreadâ. The technology of weaving fabric from natural fibres dates back to the Middle East around 4000 BCE (before the common era) or...