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730 results in Industrial manufacturing, and operations engineering

Page 11 of 37

  • nine - Conflict over public space

  • Edited by Juan Carlos Munoz, Pontificia Universidad Catolica de Chile Escuela de Ingenieria, Laurel Paget-Seekins, Pontificia Universidad Catolica de Chile Escuela de Ingenieria
  • Book:
    Restructuring Public Transport through Bus Rapid Transit
    Published by:
    Bristol University Press
    Published online:
    01 September 2022
    Print publication:
    10 January 2016, pp 163-180

  • Summary

    Introduction

    Bus Rapid Transit's (BRT) promise for sustainability is more than improving public transit accessibility, it is also that by design BRT dedicates public space for bus and, in some cases, non-motorised users. Shifting space away from personal cars is a radical act that can have impacts beyond benefits for bus operations. It has the potential to reshape urban development away from car-centred cities. However, achieving this potential will result in conflict.

    The reality is that transportation requires physical space and in urban areas the amount of space is limited. Decisions have to be made about whose mobility needs or what type of mobility (non-motorised, public transport, personal vehicles) is prioritised in the design, management, and enforcement of street space.

    The competition for space generates conflicts, which are both physical and political (Vasconcellos 2001). The conflicts are not always explicit, but there are no neutral decisions. As Vasconcellos (2001, p. 71) notes, ‘Every circulatory space is physically marked by past politics, revealing the dominate interests that shaped them’. The political conflicts can be just as challenging for BRT implementation as the institutional challenges discussed in Section 1 and operational challenges discussed in Section 3 of this book.

    How governments and BRT implementers respond to conflicts has substantial impacts on the success of BRT projects and the ability of BRT to significantly reshape cities and contribute to sustainability. This chapter uses four transport projects with dedicated busway components, in cities with a high proportion of non-motorised and/or public transit users, in order to examine how governments respond to conflicts over space and the impact on the outcome of the project.

    Theoretical framework

    Conflicts over transportation take place within the context of automobility. Automobility is the reliance on private motorised vehicles for mobility, but also a theoretical concept to describe how private car trips have been prioritised and have shaped not only the urban fabric of cities, but people's relationship to time and space (Sheller and Urry 2000). The reliance on cars did not just happen, but is the result of specific political decisions. Mobility is both created by and creates the production and distribution of power; there are struggles over which transport modes are prioritised in terms of resources and space (Cresswell 2010; Henderson 2004).

  • sixteen - Assessing corridor performance

  • Edited by Juan Carlos Munoz, Pontificia Universidad Catolica de Chile Escuela de Ingenieria, Laurel Paget-Seekins, Pontificia Universidad Catolica de Chile Escuela de Ingenieria
  • Book:
    Restructuring Public Transport through Bus Rapid Transit
    Published by:
    Bristol University Press
    Published online:
    01 September 2022
    Print publication:
    10 January 2016, pp 299-316

  • Summary

    Introduction

    Public transport systems are increasingly aiming at providing an integrated service for the user. In these systems, BRT is a key component since it can provide a fast trip to users in congested urban setting. The promise of BRT is not just that it can be delivered at a fraction of the cost of a rail-based system and considerably faster, but also that it can provide an equivalent level of service and capacity. This combination of cost and performance leads to the growing global interest in BRT as an urban passenger transport solution in situations typified by maximum peak hour ridership often in the range 7,000 to 45,000 passengers per hour per direction.

    As discussed in Chapter Fifteen, public transit should be designed, implemented, and evaluated as a system. BRT can either play the role of a main structural spine of the system or of a high capacity feeder from the periphery into a rail network. In cities without an integrated system BRT can also be implemented on its own, but as a building block toward a full system. In any of these cases, the basic unit of BRT is a corridor; its potential to attract demand and to offer a high level of service depends on the characteristics of the corridor.

    Using the corridor as a unit of analysis is limiting since it does not address overall system performance. But corridor performance measures can provide valuable insight into how to improve operations on existing BRT corridors and act as inputs into the decisions around new corridors. Understanding the relationship between the operational performance of a corridor and its design characteristics is crucial when planning, designing and implementing a BRT corridor.

    In this chapter we identify key performance measures and focus our analysis on ridership and operational performance. For the latter, we discuss how to improve speed, frequency, vehicle load, and reliability. The results are based on studies with samples from BRT systems around the world.

    Of course, the urban context of any BRT corridor affects its performance. In some contexts some of the high productivity opportunities could be much harder to implement than in others. Thus, corridor planners need to consider their local conditions in addition to these results.

  • fourteen - Opportunities provided by automated data collection systems

  • Edited by Juan Carlos Munoz, Pontificia Universidad Catolica de Chile Escuela de Ingenieria, Laurel Paget-Seekins, Pontificia Universidad Catolica de Chile Escuela de Ingenieria
  • Book:
    Restructuring Public Transport through Bus Rapid Transit
    Published by:
    Bristol University Press
    Published online:
    01 September 2022
    Print publication:
    10 January 2016, pp 263-280

  • Summary

    Introduction

    In much of the developed world public transport operators and authorities are beginning to take advantage of the opportunities presented by the increasing deployment of automated data collection systems (ADCS). For example, the use of automatic vehicle monitoring systems to measure on-time performance for bus service and to provide accurate real-time information to customers on when a bus will arrive at a particular stop. Similarly, automatic fare collection systems such as contactless smart cards can give a clear picture of system usage at the individual customer level, information previously available only through quite expensive and unreliable customer surveys. However, even in the most advanced organisations the full potential of these systems is far beyond current uses.

    In urban areas of the developing world the opportunities presented by the introduction of ADCS are even greater because of the typical paucity of data, especially in the case of informal public transport markets. Some level of formalisation will be required to take advantage of the benefits of ADCS. A fragmented service delivery model, where each bus owner may own one or two buses, provides neither the financial incentive nor the operational capacity to allow the effective deployment of ADCS technology.

    Bus Rapid Transit (BRT) requires a significant increase in information if it is to be run efficiently and provide a high level of service. Customers rightly expect accurate information on how long they must wait for a bus serving their destination to arrive at their station and how long it will be before they get there. Operators need to be able to estimate the productivity and reliability of individual vehicles and drivers, as well as the productivity and reliability of each route operated. Automated data collection systems are fundamental to this type of performance monitoring. Even in developing cities, with current high public transport modal shares, for BRT to be successful in the long term as incomes increase, it will need to offer a service quality providing high customer satisfaction. These systems can also provide rich information for route and network planning.

    In this chapter we describe the roles that ADCS can play in improving public transport performance and illustrate several of them through case studies from recent research.

  • seventeen - BRRT: adding an R for reliability

  • Edited by Juan Carlos Munoz, Pontificia Universidad Catolica de Chile Escuela de Ingenieria, Laurel Paget-Seekins, Pontificia Universidad Catolica de Chile Escuela de Ingenieria
  • Book:
    Restructuring Public Transport through Bus Rapid Transit
    Published by:
    Bristol University Press
    Published online:
    01 September 2022
    Print publication:
    10 January 2016, pp 317-336

  • Summary

    Introduction

    To achieve high satisfaction indicators, a public transport system needs to provide a high level of service to its users. A high level of service not only requires that users experience low waiting times, fast travel times, and a minimum comfort standard, but also that this service is reliable – that is, it does not change significantly from day to day. These expectations explain some of the success of heavy rail systems around the world. However, heavy rail has a high infrastructure cost, ranging between US$70 and US$350 million per kilometre (Wright and Hook 2007). This cost makes rail an unattractive alternative for corridors with passenger demand under 20,000 passengers per direction per hour, and makes it very often too expensive for most developing countries. These are precisely the countries where demand for public transport is high.

    To overcome these problems, Bus Rapid Transit (BRT) has arisen as an alternative to rail potentially offering the same level of service at a reduced cost. BRT bases most of its high level of service on rapidness. The Rapid in BRT stands for both the speed of the buses and their frequency. High frequencies create shorter trip times and higher capacity. This reduces waiting times and improves comfort, two critical elements of the level of service perceived by users. In the developed world, low frequency services (fewer than six buses per hour) are often operated with schedules. Under this scheme, passengers may experience not just a low wait time, but a reliable service. However, operating a medium or high frequency service on a timetable is not only challenging, but also inefficient since cycle times would be increased by extra travel times needed for buses to reach control points on schedule. Thus, most BRT services commit to an average frequency, not a schedule. Even though segregated lanes help isolate bus operations from general traffic, BRTs operation is still affected by traffic signals and demand fluctuations. It is well known that such perturbations affect the regularity of bus headways, inducing what is called bus bunching, where buses travel together. This phenomenon happens because buses trailing a longer than average headway get more loaded than usual, and therefore run more slowly than the average bus.

  • four - BRT as a tool for negotiated re-regulation

  • Edited by Juan Carlos Munoz, Pontificia Universidad Catolica de Chile Escuela de Ingenieria, Laurel Paget-Seekins, Pontificia Universidad Catolica de Chile Escuela de Ingenieria
  • Book:
    Restructuring Public Transport through Bus Rapid Transit
    Published by:
    Bristol University Press
    Published online:
    01 September 2022
    Print publication:
    10 January 2016, pp 51-72

  • Summary

    Introduction

    Government authorities in cities across the global south embrace disruptive technologies, such as Bus Rapid Transit (BRT) and system integration (see Chapter Three), not only as lower cost alternatives to heavy rail, but as mechanisms ‘to establish effective regulatory control over largely privatized transit systems’ (Hook 2005, p. 184; see also Corporación Andina de Fomento 2010, p. 24; Hidalgo and Huizenga 2013, p. 76). In many of these cities, loosely regulated consortia of vehicle owners are entrenched as the dominant suppliers of services, and their operations contribute to many urban ills, such as pollution, accidents, congestion, noise and petty crime. In turn, authorities are limited by severe budget constraints and by weak enforcement capacity. Where this combination arises, the adoption of new transit technologies like BRT can serve as a tool to restructure the existing industry and renegotiate agreements governing service. The growing appeal of these technologies is at least partly based on two critical assumptions: (1) that the savings resulting from the rationalisation of routes, vehicle fleets and administrative functions will suffice to cover costs currently ignored by existing private operators (such as timely vehicle maintenance, fleet replacement, cleaner fuels, driver training and benefits, taxes, parking and maintenance facilities); and (2), that most users care about transport externalities enough to accept at least some inconveniences (for example, having to make additional transfers, walk greater distances to stops, board more crowded buses or spend more time waiting).

    While project planners frequently accept these assumptions, they usually relax initial expectations when confronted with cost and performance tradeoffs. In most cases, such as Cape Town and Johannesburg, South Africa, the potential disruption and cost implications of an envisioned citywide transit reform has constrained implementation to a few showcase corridors, leaving the vast majority of transit trips to be served with little change in the incumbent providers. In a few other cases, such as Leon, Mexico, Seoul, Korea and Santiago, Chile, authorities set out to rationalise the entire public transit network, but adjusted their aims once the financial cost to taxpayers and inconvenience to users became evident. Paradoxically, authorities rely on the continued involvement of at least some of the same private operators that they initially sought to replace, not only to defuse their opposition to implementation, but also as a means to lower the costs of formalisation and to reduce the strain on users.

  • nineteen - Road safety impacts of BRT and busway features

  • Edited by Juan Carlos Munoz, Pontificia Universidad Catolica de Chile Escuela de Ingenieria, Laurel Paget-Seekins, Pontificia Universidad Catolica de Chile Escuela de Ingenieria
  • Book:
    Restructuring Public Transport through Bus Rapid Transit
    Published by:
    Bristol University Press
    Published online:
    01 September 2022
    Print publication:
    10 January 2016, pp 355-368

  • Summary

    Introduction

    Traffic accidents account for over 1.2 million annual deaths around the world, and this number is expected to increase, making road fatalities one of the leading causes of premature mortality worldwide by 2030 (World Health Organization 2013). The increase in traffic fatalities is expected to be concentrated in low and middle income countries, which are now experiencing a significant growth in motorisation. With the recent increase in the popularity of Bus Rapid Transit (BRT) systems worldwide – over 180 cities featured some type of BRT system by 2014 – there is an opportunity to jointly tackle the traffic safety and mobility issues faced by developing world cities.

    BRTs are usually implemented on high demand corridors, particularly urban arterials, which are typically the most dangerous types of roads in urban areas. Research from New York City, for instance, has shown that arterials represent only 15% of the road network in a city, but concentrate over 65% of severe crashes (Viola et al 2010) and data from the developing world indicate similar trends (EMBARQ 2014). While there is a potential concern that implementing a BRT along a busy arterial road may attract pedestrians to areas of high risk, this is also an opportunity to improve the infrastructure and achieve significant safety benefits. Evidence from BRT implementation in Latin America and Asia supports this claim (Table 19.1), as BRT systems in these different regions have shown positive safety impacts. Our research shows that the safety improvements are due to the changes to the street geometry needed to accommodate the BRT infrastructure (for example, lane removals, medians, turn prohibitions).

    In this chapter, we provide an overview of the results of BRT safety impact assessments, with a brief discussion of the methodology and its challenges. We then explore the infrastructure components of BRT that contribute to the safety impacts. We conclude by discussing how safety countermeasures specific to BRT corridors can impact the system's operational performance.

    Evidence on the safety impact of BRT

    The traffic safety aspects of BRT systems are typically not as well understood as their better documented impacts on travel times, greenhouse gas and local pollutant emissions, or land values. However, our research shows that BRTs in Latin America and Asia have had significant positive impacts on traffic safety, reducing injuries and fatalities by upwards of 50% on the corridors where they were implemented (Duduta, Lindau and Adriazola-Steil 2013; Duduta et al 2014).

  • fifteen - Designing a BRT-based network under integrated operations

  • Edited by Juan Carlos Munoz, Pontificia Universidad Catolica de Chile Escuela de Ingenieria, Laurel Paget-Seekins, Pontificia Universidad Catolica de Chile Escuela de Ingenieria
  • Book:
    Restructuring Public Transport through Bus Rapid Transit
    Published by:
    Bristol University Press
    Published online:
    01 September 2022
    Print publication:
    10 January 2016, pp 281-298

  • Summary

    Introduction

    Network design usually refers to the stage in public transport planning where the routes and frequencies are defined for the services in a public transport system. However, network design can also consider more strategic decisions, such as which transport modes will be involved, and how they will interact in the system. Designing a network is a very complex problem which spans economic, environmental and social aspects, involving a great variety of actors with conflicting interests. Passengers, for instance, are interested in a transit system with low fares, high frequency and direct, fast journeys; private car users may prefer a system that reduces traffic congestion without taking up car space; driver unions will care about the drivers’ working conditions; and operators may be interested in providing highly productive operations at low costs. All these trade-offs must be faced at the design stage, and good coordination of the involved bodies will play a decisive role in the successful outcome of the projected system. In addition, there are no blank slates and cities have to build on existing transit networks, operators, and travel and land use patterns. Chapter Three discusses some of the challenges in implementing a new integrated system.

    Whether Bus Rapid Transit (BRT) is introduced in an existing formalised transit system or used as a tool to formalise an informal bus sector, the service network will be questioned. In the case of a city already operating under formalised services, the integration between those services and the new BRT corridor should be discussed. Will previous services running parallel to the corridor be cut, changed by shorter feeder services or allowed to enter the corridor? How will the interchanging infrastructure between feeder buses and other modes be built? The implementation of a BRT corridor presents an opportunity to re-evaluate not just the routes, but also the network configuration. For example, if a system is being operated using point-to-point services, some of these services could be rerouted to use the capacity and improved speed of the BRT corridor. In some cases even a switch to something closer to a trunk and feeder network configuration could be justified in the presence of new BRT corridors and fare integration. This type of decision is further discussed in the next section of this chapter.

  • one - The promise of BRT

  • Edited by Juan Carlos Munoz, Pontificia Universidad Catolica de Chile Escuela de Ingenieria, Laurel Paget-Seekins, Pontificia Universidad Catolica de Chile Escuela de Ingenieria
  • Book:
    Restructuring Public Transport through Bus Rapid Transit
    Published by:
    Bristol University Press
    Published online:
    01 September 2022
    Print publication:
    10 January 2016, pp 1-14

  • Summary

    The promise of Bus Rapid Transit

    Cities, or perhaps more accurately urban conglomerations, are the engines of economic growth and human development, but face numerous well documented challenges in the twenty-first century. Cities are increasingly forced to compete for capital in a globalised economy, but at the same time are the cradle of creativity and prosperity. Population and income are growing, and along with them motorisation rates, trips per capita, traffic congestion, inequality, and social segregation. These problems are compounded by a sense of urgency about the need to address climate change, air pollution, traffic injuries and deaths, and lack of physical activity.

    Despite the seemingly insurmountable challenges, cities provide opportunities to shift urban development to a more liveable and sustainable pattern. Sustainable cities should continually reduce their environmental footprint, while shrinking social inequity and creating a stable long term economy that can meet the demands of the current and future population. Delivering on this triple bottom line agenda requires substantial changes to the existing design and management of urban space. As a major driver of urban space, transportation is a key element of both the problems and the solutions for urban sustainability.

    Over the past 100 years, cities have increasingly been designed for the needs of cars – ample parking, capacity to meet peak-hour demand, roads designed to increase speed. At the same time land use has been planned for low density and single uses, forcing people to use cars, even for the simplest trips. However, a sustainable city should shape urban space around the needs of people, with transportation being for multiple uses and with multiple transportation modes possible.

    The ability to meet peak-hour transportation demand is a key concern in urban areas. In the peak hours, when large numbers of people want to arrive in the same area at the same time, the car is clearly a problem from a social perspective. Cars do not use urban space efficiently (especially with the use of cars being underpriced in most cities), causing significant congestion and creating air pollution, particularly at low speeds. In order to avoid the problems associated with the use of cars during peak periods, cities need to have a high share of sustainable transport modes, including walking, cycling and public transport.

  • three - The path toward integrated systems

  • Edited by Juan Carlos Munoz, Pontificia Universidad Catolica de Chile Escuela de Ingenieria, Laurel Paget-Seekins, Pontificia Universidad Catolica de Chile Escuela de Ingenieria
  • Book:
    Restructuring Public Transport through Bus Rapid Transit
    Published by:
    Bristol University Press
    Published online:
    01 September 2022
    Print publication:
    10 January 2016, pp 31-50

  • Summary

    Introduction

    The main goal of an urban transport system is to provide accessibility for the inhabitants of an urban region. As this book shows, Bus Rapid Transit (BRT) projects can play an important role in urban mobility, but they cannot stand alone. A combination of different transport modes is needed to serve the demand which varies across different times and geographical areas of the region. Residents have to navigate the transport system to reach their destinations. The service they receive depends on the characteristics of each of the segments they must follow (including the access to and egress from public transport) and the experience of transfer between them. The system will provide a higher level of service to its users if it is designed for passengers to move between trip legs as smoothly as possible, and if they understand the system's inherent complexity so as to be able to find their best possible route choice (see Chapters Twelve and Thirteen). The more convenient transfer experiences are within the system as a whole (for example, no additional fare and a short walk), the better the use that passengers will make of the available network of services. Alternatively, passengers may avoid certain service combinations due to inconvenient transfer experiences. Thus, users (and therefore the urban region) will always benefit from offering an integrated system with seamless transfers.

    An integrated network that provides seamless access between all points is ideal; however, this is a complicated undertaking, especially when the system is fragmented into different authorities or decision makers, or when the starting point is an informal bus network, as described in Chapter Four. In this chapter we discuss the challenges faced by two integration pathways – sudden and gradual – and suggest a framework for advancing public transport integration which mitigates the main issues observed in these cases. The framework is designed for implementing integrated public transport systems in a context where regulation is insufficient and multiple private operators are involved. We found that this context is quite common, particularly in developing countries.

    The issue of public transport integration

    Integration has been a recurring topic in transport policy. Preston (2012) traces back the policies for transport integration in the UK to 1947 and in Europe to 1952, but indicates that integration has proven hard to achieve in practice due to the difficulty of defining and operationalising integration.

  • eight - Fare structures

  • Edited by Juan Carlos Munoz, Pontificia Universidad Catolica de Chile Escuela de Ingenieria, Laurel Paget-Seekins, Pontificia Universidad Catolica de Chile Escuela de Ingenieria
  • Book:
    Restructuring Public Transport through Bus Rapid Transit
    Published by:
    Bristol University Press
    Published online:
    01 September 2022
    Print publication:
    10 January 2016, pp 145-160

  • Summary

    Introduction

    Customers pay fares for the services they consume on public transport and fares are the means by which operators receive a contribution to the cost of service provision. This simple exchange belies a complex set of decisions in every urban area which have far reaching impacts beyond the operation and use of the public transport system. It affects the accessibility of citizens and ultimately impacts on urban form.

    A fare system is defined by its structure, its collection method and the fare level. The objectives for public transport guide how these three elements are combined. For instance, a transport authority may use fares as a tool to meet policy objectives such as demand management to reduce congestion or subsidy allocation to promote equity or social inclusion. In this chapter, we are concerned with the fare finally paid by the user in contrast to the technical fare (BRT Planning Guide (ITDP 2007)), which is related to the amount per passenger received by the operator and how this is related to efficiency and incentives (Laffont and Tirole 1993), which is more properly considered as a part of the contract design (see Chapter Seven).

    The implementation of a BRT system as new infrastructure offers an opportunity to reinforce government objectives because the process usually introduces regulations and contractual agreements that allow the authority to set fare fixing criteria consistently. In the case of urban areas with unregulated bus transport systems, such as many cities in developing countries, BRT implementation is also an opportunity to harmonise transport in the city by regulating the fares of previously unregulated operators either by offering a substitute mode with a regulated fare, which could be lower, or by giving incentives to complementary services to agree an integrated fare system. New BRT or integrated systems are however different from the many unregulated services they replace since the latter typically operate without subsidy and behave like typical ‘firms’.

    It is important to understand the overarching goal of a BRT system – whether the objective is to maximise the number of passengers, maximise the revenue or to reach some other specific goals such as commercial cost recovery or to benefit some sector of the community, such as the socially excluded. It is clear that cities cannot expect to meet all these goals at the same time and that they will have different implications for fare levels in particular.

  • Preface

  • Lakhwinder Pal Singh
  • Book:
    Work Study and Ergonomics
    Published online:
    17 August 2019
    Print publication:
    02 December 2015, pp xxi-xxii

  • Summary

    This book has been especially written and prepared for undergraduate and post-graduate students of industrial engineering, production engineering, industrial and production engineering, mechanical and industrial engineering or mechanical engineering, pursuing a one semester course on work systems design, work safety and ergonomics, work design and ergonomics, work study and ergonomics, industrial ergonomics, occupational health and ergonomics, or industrial engineering and ergonomics. Normally the course is offered as a single semester course. But in the present text it has been the author's endeavour to cover not only what can be taught in a single semester but also provide some additional material needed by an ergonomist or an occupational safety engineer. The present text is supplemented with the case studies and live examples from the industry. Hence, human factor engineers or occupational safety engineers or work study engineers will benefit from the knowledge on practical applications of Work Study and Ergonomics.

    Chapter 1 explains the basic concepts, definitions, scope and importance of productivity, reasons for lower productivity, and methods to improve the same followed by integration of work study and productivity. Chapter 2 describes the role of human factors in work study, and the qualities of a good work study man. Chapter 3 deals with the concepts, definitions and applications of method study, procedural steps to conduct methods' study, different tools and techniques for methods' study; followed by principles of motion economy, therbligs and work simplification. Subsequently Chapter 4 focusses on basic techniques of work measurement, work sampling, and stopwatch time study procedure, equipment and forms for time study, allowances, rating scales, calculation of basic and standard time; followed by some numerical problems. As the standard time calculated through work sampling or stopwatch time study is useful for deciding wage rates and incentives for the workers and employees, hence Chapter 5 is dedicated to various wage and incentives schemes and programmes.

    By the end of Chapter 5 the students would have acquired an understanding of work study, its importance and its role in industry. Consequently they will be able to conduct motion studies, time studies, set time standards and apply them in fixing wages and incentives for the employees/workers of an organization. Given this, Chapter 6 of the book will introduce the students to the basic concept of ergonomics, to the historical evolution, scope and objectives of ergonomics, …

  • 7 - Work Physiology

  • Lakhwinder Pal Singh
  • Book:
    Work Study and Ergonomics
    Published online:
    17 August 2019
    Print publication:
    02 December 2015, pp 145-161

  • Summary

    Introduction

    This chapter focuses upon the physiological aspects of muscular work, and it describes how various physiological systems work together to meet the energy expenditure requirements of work load and how these requirements can be measured quantitatively and considered in the analysis of physical work. Whereas in subsequent chapters the focus is on the mechanical aspects of physical work and awkward postures and heavy exertion forces that can lead to severe musculoskeletal problems, such as low-back pain and upper-extremity disorders.

    This chapter begins with a depiction of the physiological structure of muscles and how energy is generated and made available for use by the muscles. Subsequently, it describes how the raw materials for energy production are supplied and its waste products removed by the circulatory and respiratory systems. The human body has a musculoskeletal system of bones, muscles and connective tissues which enable it to uphold the body posture, walk and run and lift and carry objects. Physical work is possible only when there is sufficient energy/vigour to support muscular contractions. Energy expenditure requirements of various types of activities are then described, together with a discussion about how the levels of energy expenditure can be measured quantitatively. Clearly, there are upper limits of energy production and muscular work for each individual. The implications of these work capacity limits for ergonomic job design are discussed in the last section of the chapter.

    Muscle Structure

    The primary role of muscle is to generate force and produce movement by exerting forces such as pull and push. The human body has mainly three types of muscle cells, also called as muscle fibres. However, this chapter is primarily focused upon the skeletal muscle, since it is directly responsible for physical work, these are described below.

  • (a) Smooth muscles

  • (b) Cardiac muscle

  • (c) Skeletal muscles

  • (a) Smooth muscles: Smooth muscles are found in the stomach and intestines, blood vessels, urinary bladder, and uterus, etc. These muscles basically help in the digestion of food and are responsible for regulating the internal environment of the body. The contraction of smooth muscles is controlled by autonomic nervous system but not by consciousness.

  • (b) Cardiac muscles: Cardiac muscle is the muscle of the heart, and like smooth muscle it is not controlled by consciousness, but under direct control of autonomic nervous system.

  • 4 - Work Measurement

  • Lakhwinder Pal Singh
  • Book:
    Work Study and Ergonomics
    Published online:
    17 August 2019
    Print publication:
    02 December 2015, pp 63-115

  • Summary

    Introduction to Work Measurement

    It has already been described in the previous chapter that work study is mainly composed of method study and work measurement. Both these components are very closely linked with each other. Method study is mainly concerned about reducing the ineffective movements and time related to the job. Whereas work measurement is investigation of ineffective time related to a task, and subsequently establishment of time standards for the job under consideration. In broader terms ‘work measurement can be defined as the application of ways or methods designed to determine the required (standard) time for a competent operator to perform a task at a distinct rate of operating’.

    Therefore, work measurement techniques are focused to find out the time required for completing an operation or an element by a qualified operator working at a standard pace and using the standard method. The time thus calculated is known as standard time. The method to do the job is normally standardized by using motion study procedure before carrying out work measurement or time study. The different commonly applied work measurement techniques are as follows:

  • (i) Stopwatch procedure for time study

  • (ii) Predetermined motion time system (PMTS)

  • (iii) Synthesis or synthesized time standard

  • (iv) Work sampling or activity sampling or ratio delay study

    • Stopwatch Time Study

    Time study was developed by F. W. Taylor and since a stopwatch is used for making time observations; therefore it is called as stopwatch time study. It is a unique technique of work measurement as it involves direct observation of work while it is performed. Time study can be defined as follows:

    ‘Time study is a work measurement technique mainly comprising of recording the data with respect to time and rate of working for the elements of the specific job being carried out under the given condition and subsequently analyze the data in order to establish the basic time (normal time) and standard time required to carry out the job at a distinct level of performance’.

    The main objective of work measurement is to facilitate the management to establish the time standards for a particular job or its elements. The established standards can be used as a benchmark to compare the results achieved in future and exercise the necessary control.

  • 18 - Cardiovascular Health of Steel Workers

  • Lakhwinder Pal Singh
  • Book:
    Work Study and Ergonomics
    Published online:
    17 August 2019
    Print publication:
    02 December 2015, pp 354-371

  • Summary

    Introduction

    In chapter 17 work related physical conditions for the protection of workers has been investigated in small and medium enterprises, which explored that managing of various enterprises lacking within this concern. Before that, it is also observed in chapters 14, 15, and 16 that employees of steel industry were highly exposed to noise, dust, and heat stress especially during the extreme weather conditions in summer season. Thus, workers working in low resource settings were found highly exposed to onsite hazardous work conditions. The present chapter exhibits a case study which investigated the effect of onsite work conditions and physical activities on cardiovascular parameters of industry workers. This chapter comprises two parts: first part explains general background of cardiovascular health followed by methods to assess the cardiovascular functions. Second part is dedicated to a case study of comparison between exposed and control group, process wise variation in the parameters and effect of duration of work experience on the cardiovascular functions (parameters). Subsequently, it describes about the influence of alcohol, smoking and tobacco consumption on the cardiovascular parameters.

    Statistical Tools used for Analysis

    As mentioned above in the introduction that, for each type of parameter two groups of population were included: one group of male subjects (workers) from casting and forging firms, i.e., exposed group and another group of male subjects from the randomly chosen non-exposed population, i.e., control group. All the parameters were statistically investigated using the t-test and ANOVA for multiple comparisons among various sub-groups with a confidence level of 95 per cent. The results were also analyzed for association of physiological parameters with habits like alcohol, smoking and tobacco ingestion. The conclusions were drawn on the basis of results and analysis.

    Cardiovascular Autonomic Control (HRV) and Work Conditions

    The working environment of steel SMEs is very risky and unavoidable. The work-related physical condition and safety measures are ignored at the workplaces (Singh et al., 2010). It has been established by Togo and Takahashi (2009) that the occupational exposure to hazardous settings along with work related stressors, and work timing had been associations with low HF component of power spectral density. The workers are exposed to noise, heat stress, dust and fumes, etc. which are known factors leading to decreased parasympathetic activity (Shannon et al., 2001 and Fujino et al., 2007).

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