Learning outcomes By the end of this unit you should be able to: detail what is meant by the term ‘e-commerce’; examine some typical distributed applications; detail some of the problems that are encountered when developing distributed applications; describe briefly some of the technologies that are used to support distributed applications; show how some of the technologies detailed in the unit are used in concert to realise a typica
Introduction This unit examines the type of system which is described by the umbrella term ‘e-commerce’. A number of typical application areas are examined including retailing using the internet, supply chain management and online auctions. The unit also looks at some of the underlying technologies used to implement e-commerce applications, for example web technology. The final part of the unit looks at some of the problems which are encountered when developing distributed e-commerce systems, for exam
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1.9 Summary Relational database systems underpin the majority of the managed data storage in computer systems. In this unit we have considered database development as an instance of the waterfall model of the software development life cycle. We have seen that the same activities are required to develop and maintain databases that meet user requirements.
1.8 Maintenance Databases are one of the more enduring software engineering artefacts; it is not uncommon to find database implementations whose use can be traced back for 15 years or more. Consequently, maintenance of the database is a key issue. Maintenance can take three main forms: Operational maintenance, where the performance of the database is monitored. If it falls below some acceptable standard, then reorganisation of the database, usuall
1.7 Testing The aim of testing is to uncover errors in the design and implementation of the database, its structure, constraints and associated user and management support. Testing is usually considered to involve two main tasks – validation and verification. Without adequate testing users will have little confidence in their data processing. Validation answers the question: has the right database been developed to meet the requirements? It attempts to confirm that the right database has been co
1.6.3 Supporting users and user processes Use of a database involves user processes (either application programs or database tools) which must be developed outside of the database development. In terms of the three-schema architecture we now need to address the development of the external schema. This will define the data accessible to each user process or group of user processes. In reality, most DBMSs, and SQL itself, do not have many facilities to support the explicit definition of the external schema. However, by using built-in q
5.4 Identifying sources So what material do you have available to you? Your materials are likely to be your first sources of information. Any guidance notes you may have been given will sometimes tell you exactly which sections you need to look at. But don't forget that your course materials encompass more than just these texts. Make use of any handouts you've been given. Your own notes of what you have been reading or watch
5.7 Drawing ideas together This key skill has used a three-stage framework for developing your skills. By developing a strategy, monitoring your progress and evaluating your overall approach, you take an active role in your own learning. But learning does not necessarily follow a path of steady improvement, it involves change: revisiting ideas, seeing things from different perspectives, tackling things in different ways. You are unlikely to be able to complete your work by working through it from beginning to end
5.5.5 Identify ways of further developing your IT skills Think about your overall IT skills and suggest areas where you feel you need to improve, based on the experience you have gained. You might find it useful to discuss with your tutor, manager, another student or work colleague how you might do this. There may be changes you feel you need to make so that you can move forward, such as trying to extend the facilities and resources available to you, changing the way you study to make best use of the time you have, or focusing on improving your own
5.5.4 Evaluate the effectiveness of your strategy Using the records in your Skills File, look back over your IT development work and think about how your decisions, and the facilities and constraints of your working environment influenced the way you tackled the task. How effective was your strategy in improving your IT skills? Identify what was and was not helpful in achieving your goals and outcomes, and assess how your own IT strengths and weaknesses contributed to this. Evaluate your achievements against the criteria you establishe
5.5.3 Present information effectively Organise your information so that you can use it to illustrate and support your arguments or point of view. To do this successfully, you must be clear about what you want to say, and how you want your audience to interpret your information. Ensure that any illustrations, graphs, diagrams and charts are correctly labelled and that you have met any particular requirements for presentations. Use the word-count facility of your word processor to help you keep within limits. Remember to proofread
5.4.6 Adapt your strategy to overcome difficulties Often plans run into difficulties because of unforeseen problems or changing circumstances. For example you may be running over your deadlines, the resources or support available to you may have changed, or your personal circumstances may have changed. Plans are only a means to an end, however. If you run into difficulties, take some time to think about what effect these difficulties are having on your plans, and what changes you may need to make to your overall strategy to achieve the outcom
7.3 Monitoring your progress Use your records or logbook to provide a reflective commentary on: what you did to help you set up and use numerical, graphical and algebraic methods and techniques to achieve your goals; for example, what you did to: evaluate information from different sources and develop alternative lines of enquiry; carry out calculations to appropriate levels of accuracy and draw on a range of nu
3 Key skills assessment units This section gives advice and guidance to help you compile and present a portfolio of selected work. You are strongly advised to read through this section so that you have an idea of what is expected. The key skills assessment units provide an opportunity for you to integrate your development of key skills with your work or study. You may choose to concentrate on skills that you need to develop and improve for your job, for a new course, or personally to help you keep abreast of new dev
1 Developing your number skills This Key Skill Assessment Unit offers an opportunity for you to select and prepare work that demonstrates your key skills in the area of application of number. This unit provides you with advice and information on how to go about presenting your key skills work as a portfolio. In presenting work that demonstrates your key skills you are taking the initiative to show that you can develop and improve a particular set of skills, and are able to use your skills more generally in your
Introduction This key skill develops your number skills in your studies, work or other activities over a period of time. To tackle all of this key skill, you need to plan your work over at least 3–4 months to give yourself enough time to practise and improve your skills, to seek feedback from others, to monitor your progress and evaluate your strategy and present outcomes. Application of number (simply called ‘number’ in this key skill) is all about using numerical and mathematical skills to f
7.2 Developing a strategy Present notes/records to show you can plan your use of information literacy skills. Include: the goals you hope to achieve over 3–4 months or so; you should indicate how these goals relate to the context in which you are working and to your current capabilities; notes about the resources you might use and what information you need to research to achieve your goals; for example, online resources, course materials, skills books, works
3 Key skills assessment units This section gives advice and guidance to help you compile and present a portfolio of selected work. You are strongly advised to read through this section so that you have an idea of what is expected. The key skills assessment units provide an opportunity for you to integrate your development of key skills with your work or study. You may choose to concentrate on skills that you need to develop and improve for your job, for a new course, or personally to help you keep abreast of new dev
Acknowledgements The content acknowledged below is Proprietary (see terms and conditions) and is used under licence. All other materials included in this unit are derived from content originated at the Open University.
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