Frame Relay - for Faster and More Efficient Data Communications ...

More documents

Recommendations

Info

Human Factors - A Key to ImprovedQualityThomas Backstrom and Nigel ClaridgeTelecom services are being developed rapidly, and introduced at an alarming pace.Both end-users and telecom network operators will soon experience how theseservices and other emerging possibilities place new and greater demands on theircommunication with the telecom system. Technical solutions must take human issuesinto account - technology is used by people in their daily lives. As the number ofservices offered increases, it will become more and more important to provideefficient interaction between the individual and the technology.Internationally, the art of creating an integrated man-machine system is known asHuman Factors Engineering, or Human Factors for short.The authors describe what Human Factors is, Ericsson's corporate policy within thearea, and the process required to create good and usable products from the humanviewpoint.human factorstelecommunication servicesstandardisationFig. 1In a changing world, where telecommunicationsis becoming a part of everyday life of the individual,variations in culture, traditions and languageplace demands on the design of telecom productsand services. Human Factors increases thedegree of usability and acceptability by makingproducts simple and easy to useEricsson manufactures and supplies productswithin a wide variety of areas - fromspecialised and complex products, suchas information systems used in fighter aircraft,to public and private telephone exchangesand consumer products such astelephone sets. Each product has its ownset of specific design requirements andconditions, based on the characteristicsand limitations of the intended users.Although there are few similaritiesbetween the design specifications for thecockpit of a modern fighter and those fora desk-top telephone set, all products - irrespectiveof the level of technology - haveone basic demand in common: they mustbe designed so as to perform well in theenvironment for which they are intended.Clearly, a fighter cockpit or air traffic controlcentre requires significantly more developmentresources than a simpler product,but how many of us have beenfrustrated, if not injured, when using a canopener. After several unsuccessful attemptswe have probably thrown it away.To avoid these problems, the way a productwill be used - and by whom - must bethoroughly analysed and the results integratedearly into relevant product specifications.In principle, there is little differencebetween the Human Factors methods appliedwhen designing a cockpit and thoseapplied in the design of a telephone set.The variation lies in the number and complexityof relevant factors, resulting incockpit design being significantly more difficultand more extensive.Historical backgroundThe need for new specialist knowledgearose because both users and manufacturersbecame more and more specialisedin their activities, and because demandsfor safety and efficiency increased. Thisknowledge identified demands to be includedin product design - demands thatwere based on the users' (operators') cognitiveand physical limitations and the worksituation. It also formulated these demandsso that they were understood andusable by the systems engineer.The need for Human Factors knowledgewas accentuated during the Second WorldWar. Technical developments advancedto such a degree that individuals operatingsystems and vehicles experienced seriousdifficulties and were exposed to personaldanger. It became necessary todesign control systems and to present informationin a way that permitted efficientoperation, yet avoided overstressing theindividual and eliminated the risk of accidents.This development has continued, and HumanFactors knowledge is now applied notonly to complex and sophisticated productsbut also to a wide range of everydayproducts, such as cars, computers, toolsand machinery and consumables. Aids forthe elderly and the handicapped is anotherarea where Human Factors knowledge isapplied.ERICSSON REVIEW No. 1-2, 1992
21NIGEL CLARIDGENomos Management ABTHOMAS BACKSTROMEricsson Telecom ABBox 1Definition of Human FactorsHuman Factors is defined as "The study of the relationbetween man and his occupation, equipmentand environment, and particularly the applicationof anatomical, physiological andpsychological knowledge to problems arisingtherefrom".Therefore, "Human Factors in Information Technology"(IT) is considered to be the study of, andapplication of Human Factors knowledge to, allaspects of the relation between the human, themachine and the environment which directly influencethe safe, efficient, acceptable and satisfyingusage of the IT system.Box 2HUMAN FACTORSENGINEERINGEricsson's PolicyPurpose To ensure high Human Factors'quality in all Ericsson productsPolicy Human Factors Engineeringshould be applied to all product design,thus making the productsprofessional also from the individualuser's and handler's point ofviewResponsibility Business Area and/or Local Companymanagement is responsiblefor the issuance of application rulesfor Human Factors Engineering.Corporate Systems andTechnology is responsible forcoordination activitiesGuiding Principles- Products and systems to be used in similar userenvironments should be given uniform economicor Human Factors properties- In product design work, great attention shouldbe paid to the concepts "user-friendliness" and"suitability for purpose"- Our professional knowledge in Human FactorsEngineering should be utilised in our marketing- Qualified application of Human Factors Engineeringshould be emphasised as importantquality improvements- Existing standards in the Human Factors fieldmust be followed and measures must be takento further develop such standardsERICSSON REVIEW No. 1-2,1992What is Human FactorsAs defined in Box 1, Human Factors is aninterdisciplinary science. The terms HumanFactors and Ergonomics are oftenused synonymously when defining boththe applied area of research and the methodused to create products. In Scandinavia,the term Ergonomics has beenstrongly identified with the physical designof products and workplaces, i.e. associatedwith man's physical characteristics relevantin this context: anthropometry,stress, vision and hearing. The term HumanFactors is used to encompass theseaspects - and also the cognitive aspects- in the design process, such as man's abilityto process, interpret and act upon information.Cognitive issues have grown inimportance as information technology hasbroken into more and more areas of application.The changing world ofTelecommunicationsAs a result of increased competitionthrough deregulation, network operators'cost situation has become strained at thesame time as subscriber demand for servicehas increased. Subscribers have becomeincreasingly dependent on the telecomservices they use. Individuals andcompanies are emphasising the need formobility; yet demanding access to the samefunctions and services irrespective oflocation. Many of these demands are nowfulfilled by both public and private exchangesand by fixed and mobile services.Common to all these changes is the demandfor simplified methods of handlingan increased range of complex services.Services must be easy to learn and easyto use for end-users, subscribers and networkoperator service staff. Handling proceduresfor a given service should be thesame irrespective of the application, whichmeans that efficient, uniform handlingcharacteristics will become one of the mostimportant competitive edges in the future.This applies both to products which arepart of the network and to products usedby subscribers when utilising network services.Efficient handling characteristicsare a result of products that are well adaptedto user requirements and the intendedtask.There are further advantages to be gainedthrough the application of Human Factors.Variations in culture, tradition and languageare taken into account, which resultsin products becoming accessible toa wider range of end-users. The applicationof Human Factors will reduce trainingtime, lead to more reliable data input andhigher productivity, and ensure that productswill be better adapted to the environmentsin which they will be used. Facedwith the trend (noticeable in many countries)of increased supplier responsibilityfor product safety, the need to designgood, safe products supported by usabilitytesting becomes paramount. HumanFactors input in product development willbecome more and more essential.Ericsson's PolicyEricsson's goal as regards Human Factorsis that all Ericsson products should meetuser requirements for comfort and safety,and at the same time promote user andsystem performance efficiency. The Ericssonview of Human Factors is summarisedin a corporate policy which has been approvedby the Corporate Executive Committee,Box 2. The policy emphasises theneed for all Ericsson products to have aprofessional design with regard to user requirements.It also expresses the need forco-ordination in these issues between thedifferent corporate units.A principal criteria put into practice is thatspecifications about usability and functionalityare integrated, at an early stage, intothe development process of completelynew or existing products.The Technical Committee forHuman FactorsEricsson Technology Council (ETC) coordinatesthe follow-up of technical developmentsin general, and also the provisionof new technology within Ericsson. Thistask is performed via a number of researchcentres, application labs and a series ofspecialised technical committees. TheTechnical Committee for Human Factors(TUHF) is one of these committees.TUHF's task is to strengthen Ericsson'scompetence within the area of HumanFactors and to ensure a uniform corporateprofile.TUHF, through a network of contacts, bothwithin Ericsson and with external institu-
Page 1: ERICSSONREVIEW1-21992Frame Relay -
Page 4 and 5: ERICSSON REVIEWBO HEDFORSPublisher
Page 6 and 7: 4Fig. 2Distributed computer environ
Page 8 and 9: Fig. 7A company's data network shou
Page 10 and 11: 8Fig. 11The frame format used for F
Page 12 and 13: 10er (DE, Fig. 12) should be set to
Page 14 and 15: Computerised System for QualityInsp
Page 16 and 17: Box 1Code39, the first alphanumeric
Page 18 and 19: 16Fig. 6Cable attenuation test at E
Page 20 and 21: 18Fig. 9Installing the Dehlfi syste
Page 24 and 25: 221 Use the user's model2 Introduce
Page 26 and 27: 24Fig. 5Advanced Human Factors desi
Page 28 and 29: Fig. 7User interface for PBX attend
Page 30 and 31: Cell-voltage EqualisersSeries BMP 1
Page 32 and 33: 30Box1CELL-VOLTAGE EQUALISER BMP 16
Page 34 and 35: 32age, the faulty cell or the entir
Page 36 and 37: In Search of Managed ObjectsWalter
Page 38 and 39: Fig. 4The telecommunication network
Page 40 and 41: Fig. 6Functional Model illustrating
Page 42 and 43: 40Fig. 9Combination of layering and
Page 44 and 45: 42Table 2Relationship between Funct
Page 46 and 47: 44No1PPI2PPI3SLTTransport Function(
Page 48 and 49: 46Table 4SDH functions, Resources a
Page 50 and 51: The Managed Objects and their prope
Page 52 and 53: 50Fig. 21Information Model of PDH d
Page 54 and 55: Fig. 25Information Model of SDH mul
Page 56 and 57: 54Table 5Cross-connect functions, R
Page 58: Fig. 32, leftCross-connect Fragment

Frame Relay - for Faster and More Efficient Data Communications ...

Create successful ePaper yourself

Delete template?

Save as template?