An investigation is presented of the impact of mechanical auxiliary devices on sewing‐machines upon the processing parameters of sewing operations. Processing parameters…
An investigation is presented of the impact of mechanical auxiliary devices on sewing‐machines upon the processing parameters of sewing operations. Processing parameters are investigated at an ergonomically designed workplace, on a modern sewing‐machine, equipped with a processing microcomputer. Measuring samples are 300 to 1,000mm long, and stitching speeds are pre‐programmed – 1,500 to 4,700rpm. Values for sewing operation processing parameters are measured and stored using the measuring system for processing parameters MMPP, developed especially for the purpose of research in the field of garment engineering. The results obtained indicate that using a tape piper the basic time needed to perform the sewing operation is reduced by up to 61.2 per cent, while the use of a hemmer reduces it by 38.3 per cent. Specific time for sewing 1m of seam is reduced using the above auxiliary devices as follows: by 64.5 per cent using a tape piper and by 41.8 per cent using a hemmer. The degree of sewing‐machine utilisation is increased by 110.6 per cent using a tape piper, and by 59.8 per cent using a hemmer. Average stitching in machine‐hand sub‐operations is increased with a tape piper from 1,041 to 3,914rpm, and from 1,176 to 3,959rpm with a hemmer. The operation structure is altered by using auxiliary devices, achieving rationalisation of the movements constituting auxiliary‐hand sub‐operations, which has a considerable impact on the processing parameters involved.
Scheduling of production in a wire rope factory is complicated byseveral features: (a) the simultaneous requirement for two types oflimited resource, machines and bobbins;…
Scheduling of production in a wire rope factory is complicated by several features: (a) the simultaneous requirement for two types of limited resource, machines and bobbins; (b) multi‐stage production with normally two or three stranding and one or two closing operations; (c) queuing at the closing machines; the typical job splits into sub‐batches when passing from the stranding to the closing operation; these sub‐batches usually queue at the closing operations which, being faster than stranding operations, generally receive work from several queues; (d) alternative choices in the selection of machines and bobbin sizes for any given stranding or closing operation; (e) the presence of random elements in the timing of machine breakdowns and repairs. In this case study factory in a developing country, the existing control of production flows was ad hoc rather than according to a specified method. The management needed to know whether a scientific scheduling approach could significantly improve the low utilisation of machines. As a first attempt a strategy was synthesised based on well‐known concepts from the theory of scheduling in static and dynamic environments, taking into consideration certain effects of the complicating factors mentioned above. Simulation revealed that a significant improvement was possible.
Job sequencing is an important stage in any hierarchical production control model, especially when a real‐time dispatching rule is not employed. The problems become…
Job sequencing is an important stage in any hierarchical production control model, especially when a real‐time dispatching rule is not employed. The problems become complicated when constraints, such as different parts requiring different operation processes at different machines and with different production priorities, are taken into consideration in the development of sequencing models. This paper first describes a mathematical programming model developed for small flexible manufacturing systems (FMS) makespan minimization sequencing problems. For large problems, a heuristic decomposition‐based algorithm is proposed. The algorithm is based on the proposed concept of track generation and track identification. Each part type may require a different number of operation processes at different machines. A numerical example is used to illustrate the use of the algorithm.
The debate about whether any difference exists between manufacturing and service operations is discussed. There is no difference per se between the two types of operation…
The debate about whether any difference exists between manufacturing and service operations is discussed. There is no difference per se between the two types of operation and that debate about differences between them is spurious. There are significant differences between operating systems which process materials and those which deal directly with customers. These differences are sufficient to require different treatment for material processing operations and customer processing operations. The similarities and differences between the two types of system are demonstrated, and strategies for managing customer processing operations are outlined. If an appropriate strategy is adopted, customer processing operations are very similar to material processing operations, but other strategies exist which make customer processing operations very different from material processing operations.
Most Western countries are demonstrating a trend in the public and private sector away from traditional manufacturing operations. This has resulted in customer‐led pressure for Production/Operations Management teachers to give service operations equal time with manufacturing. Service industries have the same operating issues as manufacturing but for effective teaching two aspects must be considered. The first is the context of service operations and the second is those differences that do exist between manufacturing and services. A teaching strategy is proposed. This emphasises the use of service cases and examples to illustrate the application of operations management approaches; an understanding of the key contextual differences in the service environment; and the development of electives focusing on specific service features in operations management. Examples from undergraduate and postgraduate teaching are given.
The concept of co‐operation amongst competitors has been considered for some time in the marketing literature generally, and in the small firm marketing literature…
The concept of co‐operation amongst competitors has been considered for some time in the marketing literature generally, and in the small firm marketing literature specifically. However, despite the recognition that small firms do co‐operate, there has been comparatively little attention paid to the ways in which such co‐operation takes place. Co‐operation amongst small firms tends to be only conceptualised as a group of competitors banding together to create a market presence and compete against larger, more established firms. Based on a series of in‐depth interviews with owner‐managers of small firms in a wide array of industry sectors, this paper examines the relationships that small firm owner‐managers maintain with their competitors. Specifically it reports that cooperation between competitors takes place at various levels with so‐called joint venture arrangements such as that described above, representing just one type of co‐operative behaviour. It further highlights the circumstances where co‐operation is likely to occur and how this co‐operation is manifest by examining the motivations for co‐operation and expected and actual outcomes. It also discusses the factors which may preclude cooperation between small firms and their competitors. Such factors include the nature of the industry sector, the level of competition in the market, the size of the competing firms, the age of the small firm, the existence of an association that represents the industry, the perceived level of professionalism within the industry and trust amongst firms.
Illustrates the need for incorporating time‐phased operator efficiency levels in apparel production plans. Presents a list of factors which predict how long it will take an operator to learn a sewing operation. Describes prediction models which use these factors to estimate time‐phased operator performance under different conditions.
To develop a theoretical understanding of leadership in stressful, complex rescue operations.
A grounded theory approach was used. Twenty rescue operation commanders from four complex rescue operations in Sweden were interviewed.
A model was developed which suggests that leadership in stressful, complex rescue operations can be understood as a causal process consisting of three broad time‐related categories. The pre‐operation everyday working conditions affect the leadership during rescue operations, which in turn affects the post‐operation everyday working conditions, etc. Everyday working conditions include training and exercises, previous mission experiences, personal knowledge of co‐actors, and organisational climate. The leadership during a complex rescue operation is affected by the leader's appraisal of the balance between what is at stake, human lives in particular, and the manageability of the situation. Patterns of stress reactions among rescue commanders and their leadership behaviour and managerial routines, were identified. Three problem areas were noted: role shifts during long‐lasting operations, staff work, and practical routines. The post‐operation conditions include the leader's evaluation of the outcome, organisational climate, and post‐event stress reactions.
Small sample, lack of representativeness, and lack of illumination of possible gender‐related aspects.
The model may be valuable in training and exercises with rescue operation commanders.
A new integrative, theoretical process model of leadership in complex, stressful rescue operations.
– The paper aims to assess the quality (content and legibility) of handwritten operation notes and the reader's interpretation of legibility by clinical seniority.
The paper aims to assess the quality (content and legibility) of handwritten operation notes and the reader's interpretation of legibility by clinical seniority.
Consecutive elective and emergency general surgical operations over a six-week period from September 2011 at one hospital were retrospectively collected. Non-retrieval of operation notes, typed notes and endoscopies were excluded. The content of each operation note was assessed against a 26-item checklist. Legibility was assessed by 4 readers (2 Foundation Doctors and 2 Registrars in General Surgery) using an original objective scoring system.
A total of 404 operations were identified; 45 were excluded following review of operation notes. Operation notes were derived from 12 consultants and 11 registrars. Analysis of the content score suggested that time of procedure (1 per cent), ASA grade (1 per cent) and blood loss (5 per cent) were poorly reported. Clinical indication and post-operative instructions were documented in only 52 per cent and 66 per cent of operation notes respectively. Registrar notes had a higher content score compared with consultant notes (15.8 vs 13.5, p<0.001). Legibility scores were reported to be higher for Registrar readers, compared with Foundation Doctor readers (OR 1.95, 95 per cent CI 1.75-2.18, p<0.001). Registrar-written notes had higher legibility scores compared with consultants (OR 19.0, 95 per cent CI 11.6-31.2, p<0.001).
The quality of handwritten notes varies. Registrar-written notes are more content-rich and legible.
Clinical seniority and specialty training may improve the interpretation of handwritten operation notes. This study adds to growing evidence supporting the widespread adoption of a computerized immediate operation note.
An objective scoring system to assess legibility of operation notes written as freehand was used. Also, legibility according to the reader's seniority in clinical training was evaluated.
The effect of situational factors on the rating ability of 28industrial analysts was determined through the use of rating films. Therating ability was evaluated in terms…
The effect of situational factors on the rating ability of 28 industrial analysts was determined through the use of rating films. The rating ability was evaluated in terms of rating accuracy and consistency. Significant differences in rating accuracy were found among the analysts from five different companies. The analysts who used time standards for planning functions surprisingly rated more consistently than those who employed time standards for a wage incentive programme. Shop labour organization, union or non‐union, had no significant impact on the analysts′ rating ability. The analysts′ rating consistency was significantly better for the medium (85‐120 per cent) and fast (125‐145 per cent) pace ranges than for the slow (60‐80 per cent) pace range. The rating consistency of the fast pace range was significantly better than the medium pace range. The familiar (machining) operations were rated more accurately and consistently than the unfamiliar (sheet metal) operations. The rating accuracy for the simple operations was significantly better than the moderate and complex operations. The simple and complex operations were rated significantly more consistently than the moderate operations.