This paper has been produced for students taking the examination in the Summer (Feburary) of 1997.

• Students are still spending far too long writing out the question. Look at X | Y below. Start this at point Y NOT at point X.

• I appreciate that for many of you, English is not your first language but it is often difficult to work out exactly what you are saying. I cannot speak for other modules in your programme, but for Open Systems, please feel free to offer short note answers. Don't waste time with long, complicated sentences.

  X	Electronic trading, the Internet, an Intranet and standards are very important in this modern world of IT, where things happen so fast.
  Y	Trading - Selling/Buying Advertising/PR/catalogues/etc Order and product progress Financial - banking/insureance/credit Electronic trading - support for trading by electronic means, specifically - EFT, EDI, on-line ordering/paying, etc.

• Please ensure that your family name is the first one in the name box on the answer sheet.

• Many of you referred to COBRA. It is CORBA - Common Object Request Broking Architecture.

• About 75% of the papers included a line something like this:

  'By making use of standards in this way, the company will be able to employ interoperability, portability and scalability.' You must not do this. It is meaninglessto throw in buzzwords. They will not impress me at all. Only use them when you are sure that their context shows me that you understand them.

• Please include as many examples as you want, especially from your work experience, but make sure they are relevant. Several students told me in details about the functionality of groupware (eg. Lotus Notes server, object tools etc) but did not explain why they were used and how they contribute to open-ness, ie. interoperability, portability or re-use.

• Please do not leave blank pages between questions. It could mean that questions get missed.

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The Questions

What follows, is each question, the assessment scheme used to mark them and then, some comments on what you might have done, or what was done wrong. I have not included model answers. I feel that with a wide subject such as this, your opinion may often be as good as mine but different. Look through the study block and the recent supplement and then draft out what you think in an answer.

Q1. Interoperation, at its highest level, is about business applications being able to work together. Bearing in mind that most applications are heavily IT-oriented, provide a review with examples, of the various levels within and between systems where interoperability is essential, showing the ways in which it might be achieved.

The 'Gandoff 7-layer model' is essential here:

Business Objectives
|
IS Strategy
|
IT Strategy
|
Business Operations/Applications
|
IT Applications
|
OS / Network OS
|
Hardware

This question need you to understand that interoperation is about business applications working together. Don't tell me about Word on an Apple interoperating with Word Perfect on a PC. This is a bad example. Instead, why not tell me about my sales system having to work with your budgeting system. Then, you can go on to show how there are problems because IT application systems are written in different languages, employ different database engines (Oracle, Infomix, etc) run under different operating systems, using different NOS and different hardware, You can then discuss ways to overcome these differences, so that the applications can interoperate.

Q2. Trade has changed very dramatically in the last few years and one of the main effects has been the requirement for enterprises to rationalise their operations and supporting IT, largely in the interests of cost-effectiveness (within their overall short- and long-term objectives).

a. Provide a review of the main pressures on the enterprise which have forced this approach, indicating how standardisation at all levels has become vital. (15 marks)

b. Discuss the advantages of this 'open systems' approach to the development of IT systems that can support current and future change in direction. (10 marks)

The first part of this fairly basic question asks you to review chapters 1/2 and classify some of the pressures on an enterprise bringing out the essential differences between business units that arise out of responses to change, why rationalisation is imperative and how a degree of standardisation can help.
Many people said that BPR (Business Process Re-engineering) was pressure on the enterprise - No! It is a response to change. If the enterprise is inefficient, look at ways to change/re-engineer its processess.

The second part is about who might be affected and how. You can bring in the buzzwords, but you must relate them to the requirement to allow for change/adaptability in the development of systems.

Q3. Concepts now considered as being particularly relevant to business operations supported by 'open systems' are electronic trading, the Internet, an Intranet and standards.
Offer an explanation as to why these concepts are so closely linked for the IT-aware enterprise.

Most of you did not understand what I wanted for 'electronic trading'. You mentioned EDI as if it was the complete answer to all trading problems using IT. Look at generate note 2 X|Y above.
Many of you said that an Intranet was the same as a LAN (this is wrong!). The Internet was essentially a platform-independent way of connecting users and sites to gather information. It is now very much more. With the ability to:

• build application logic into Web pages
• use these pages to launch many other applications
• build in increased security measures.

the web now becomes a basis for some enterprise-wide IT, especially where group working is involved.
The Intranet employs the same technology, tools and standards as the Internet, but is restricted to an enterprise and those people and companies it wants to give access to (PS: the last point would valid as an Extranet). If it was just implemented on a LAN, there would not be much point in making it 'web-aware' - employing Internet technology. The fact that it is of very wide-area significance, makes an Internet potentially so useful.

You should have mentioned the major standards that enable/support the technology. What you gave was up to you - perhaps a selection from the FTP, Telnet, HTML, HTTP, SET etc.
This is not a question to talk about portability and re-use. Some of you tried to bring systems development into it. It was looking to see if you had a broad view of electronic trading and the Web (Read up Ecommerce and Internet-EDI).

Q4.
a. In a typical LAN implementation, explain why servers are increasingly being employed to support operations and describe the purpose function of any 3 different servers other than a print server and a file server. (9 marks)

b. Trace the development of client-server (C-S) architecture, showing clearly what are essential requirements for C-S and where and why multi-tier C-S is becoming widely employed. (16 marks)

This question was deliberately set to contain a trap. The study block supplement says that lots of servers and lots of clients is NOT client-server.

a. The two main reasons why servers are employed in LANs are:
(i) services can be centralised and hence controlled and managed.
(ii) they can be shared - everyone with access priviledge can make use of them, instead of providing them for individual users.

The commonest server are:
(i) File - holds and makes available data, whether files (flat) or database
(ii) Library - holds all applications software to be downloaded to clients as required. (Most people do not separate this from the file server - the file server is often thought of as the place where data and software is stored).
(iii) Print - supplies a printing service, often from a range of printers
(iv) Gateway/Comms - allows users to make connections outside the LAN.
(v) Mail - holds user mailboxes and contains software to support and managed e-mail.

You are asked servers other than file and print - database server is cheating - it is the same as a file server.

• Web server - surrely by definition, this is not providing a service within the LAN
• Lotus Notes server - clever, but again not just within a LAN.

b. This was designed to see if you knew anything about the client-server idea and where it came from. If you told me more about LAN servers and clients - you didn't get many marks.

I wanted to hear about why client-server took over from dumb terminals and mainframe and the essential requirements for client-server. It does not just mean a client machine getting some service from a server - there has to be some degree of itneroperation - the client has to do some of the work too.
You have to mention 'middleware' somewhere in the answer. The problem with client-server is that there may be incompatibilities between the client and ther server:

• dofferemt database software
• different comms networks
• different operating systems

In addition, certain rules may apply in relation to which clients can access which services and when.
The extra tiers in the client-server complex are to resolve the incompatibilities and obey the rules.
Telling me about how OLE and how an Excell worksheet could be a server of a Word document might be correct, but it does not convince me you understand client-server (note that different between software and hardware, Gandoff is more interested in the hardware definition of C-S - look at the supplementary study material).

Q5. Explain what is meant by the term object-broking and show how the definition and adoption of standards can assist iin system component re-use and portability.

This question was badly done. Only one person spelt CORBA properly. Most people told me about encapsulation, inheritance and polymorphism etc. You just did not understand what object broking actually is. Instead, you told me about object-oriented programming. 'Quite simply', objects are activated by receiving messages. An object is represented by a piece of software, to which parameters must be passed. Object broking, in its simplest explanation, is the method or environment in which objects can be activated by applications or other objects that relies on a number of agreed standards (whether proprietary or more open). OLE (and more recently ActiveX), are the proprietary approach adopted by applications (payrool, stock, order processing, customer enquiry etc) written with the aid of Microsfot class libraries, DLLs etc, to work with each other, apparently seemlessly.

The Object Management Group (OMG) is an association of many vendors with an interest in object-orientation and were responsible for the specification of a more open Object Request Broker (ORB) and the Common ORB Architecture (CORBA - not COBRA), a framework for allowing objects in different 'environments' to communicate.

If standards such as these are followed, it should mean that objects and whole programs can 'communicate' with others leading to portability between platforms and the re-use of components in different applications.

Q6. Microsoft NT is a proprietary product while UNIX is completely open.

a. Show clearly what is meant by the underlined terms and offer your views on the validity of the statement. (10 marks)

b. The cost of changing over from one operating system to another may be prohibitive. Review, with examples, the possibilities that allow application A running hardware platform B under operating system C to interoperate with application X on hardware platform Y running operating system Z.

a. There are three aspects to this part of the question:

• What axactly does 'proprietary' mean and what is its significance.
• What is 'Unix' and is it 'open'
• When does 'proprietary' become 'de facto open'.

I think the only definition of 'proprietary' (even if very simple) is 'a product that is producex by one vendor'.

NT is proprietary - it was developed by Microsoft. However, they have made the libraries and interfaces available so that developers can build systems that run nicely under NT (as they do/did under Windows 3.x/95). Many of you said that it is proprietary because it runs on Intel. It also runs on SPARC, Alpha and other hardware so this can't be correct. The original source code for an otherpating system call 'Unix' was made available to whoever wanted it. Different organisations amended it to suit their hardware and operating requirements so that there are now a fair number of different versions.

The POSIX committees defined an environment in which a conforming operating could communicate with applications and other conforming operating systems. More recently, 'Spec 1170' laid out a range of features that 'a proper Unix' ought to conform to and even more recently the Open Group (formed from X/Open and the OSF) now can ive the brand 'Unix 95' to any Unix that conforms to a set of standards derived from Spec 1170. For more details, see the supplementary study material.

b. All about interoperability and covering much of the material of question 1! don't pick a particular operating system, or hardware platform. Instead think of two organisation (or parts of one organisation):

Either (or all) item(s) in a column might be different from the other column. What can the user department do about it? To request the IT developers to find ways to make the business applications work together before you start buying new hardware or converting databases etc:

• Try to rationalise the business applications to make them more compatible (possibly extending some of the business rules associated with IT systems).
• Find interfacing mechanisms that partly overcome differences (eg. FTP files from one system to another, allow users to Telnet from one system to another, send Lotus or Excel files between systems).
• Consider the possibilities of the Internet/Intranet which of itself supports a degree of hardware and software platform-independence.
• Consider making the operating systems compliant
• Examine the possibilities for using middleware packages.