OO: a model solution?

Object-oriented (OO) development techniques are destined to become tomorrow's technical necessity, Candice Goodwin reports

The words of the Red Queen in Alice Through the Looking Glass (above) might equally be uttered by any IT manager today. The growing importance of IT to business, combined with the growing complexity of software systems, means that the IT function is running hard just to stay where it is.

Competitive benefits

For Logica customers around the world, the need to find faster, more effective ways of providing IT solutions to business problems is fuelling an upsurge of interest in object-oriented (OO) development techniques.

"If it takes you 18 months to bring out a new application, you're just keeping up with the rest, not getting any competitive benefit from your development investment," argues Denis Howlett, from Logica's Cambridge division. "OO will inevitably take over from structured programming, because projects are getting more complicated and we need ways of helping us to manage that complexity."

The OO approach can provide benefits in terms of speed and flexibility throughout a project lifecycle. In the early stages it can help make complex systems manageable by providing better system modelling techniques. At the other end of the cycle, applications developed using OO are generally easier to change and maintain.

"An object is a better representation of what happens in the real world than an entity used in a conventional entity relationship diagram, because it encapsulates both data and program logic," explains Ned Newton, account manager in Logica's investment banking division.

"So you can, for example, have a bank account object which has procedures for withdrawals and deposits built in. At the highest level of the model, people will see objects that are quite familiar to them, such as accounts, customers, financial instruments and portfolios. Then, as you move down through the model, mechanisms such as class hierarchies and inheritance make it much easier to add detail; for example, to define different kinds of accounts."

The encapsulation of data and logic is particularly powerful when it comes to modelling distributed systems, providing a well-defined interface between objects that makes it easy to add and remove new services.

Scandinavian company SMART is exploring the benefits of OO design for a complex distributed system. SMART electronically distributes travel information from over 60 sources to travel agents throughout Scandinavia. Logica in Sweden is working with the company to develop a new range of systems giving businesses and members of the public direct access to this information.

"As part of this project, we are investigating the potential of OO to provide a uniform, extensible model of application information, such as timetables, trips and bookings, and to allow a clean separation between the model and external interfaces," explains Justin Forder, also from Logica's Cambridge division. "This will enable SMART to use a variety of user interfaces, such as voice response, interactive teletext and dial-in PC links, and will also cater for the different communications media and message formats used by individual information providers."

Commonality

Gunnar Widén, project manager at SMART, expects use of OO to increase the commonality between the company's application systems. "We have a variety of systems offering the same services through different distribution channels and hope to use the same objects to represent travel services in all these systems," he says. "This also applies to communication with information providers - the dialogues with rail and ferry companies, for example, are similar and we intend to use objects to capture this commonality."

Other Logica clients have moved on from the design stage to exploring the benefits of OO in the development and maintenance phases. The technology, with its strong support for software reuse, enabled Logica to develop a major new client/server resource management product for software house Lucas Management Systems.

"We did this in an extremely short timescale - development started at the end of September and we went into acceptance testing in January," says Denis Howlett. Called Artemis Resource View and forming part of Lucas's Artemis Views range, the product was introduced to clients in February.

But as well as development productivity, Lucas had longer-term benefits in mind. The software company recognised the vital importance of having products which are easy to maintain and extend, so that new functionality can be added quickly and cost-effectively to meet market demands. Lucas believes that, for a number of reasons, the OO approach creates systems that are easier to adapt.

Features such as inheritance also create a more robust environment for making changes to a complex system. "For example, in one instance where our carefully-designed on-screen buttons turned out to be too narrow to accommodate the German version of commands, we could change the width of the buttons throughout the system just by changing the class definition," recalls Jake Holloway, Lucas business manager.

Reliability is vital in a commercial software product, but is particularly hard to achieve in a complex client/ server system. Here again, Lucas saw advantages in an OO approach. While structured programming theory has always emphasised the importance of building programs as a series of self contained modules, which can then be changed with minimum impact on the rest of the system, OO techniques take this concept one stage further. "OO enforces low-level modularity that in turn provides a very clear system design in which each object has a well-defined role and expected set of results," explains Holloway.

Flexibility and ease of maintenance and enhancement were essential for the UK Defence Evaluation and Research Agency (DERA) who commissioned Logica to develop a number of simulation facilities, evaluating the operational effectiveness of future defence capabilities in what is a rapidly changing defence market.

Object oriented techniques have delivered significant benefits. The simulation is brought directly to the defence analyst's desktop, creating an integrated and responsive approach to meeting their needs. Study timescales have been dramatically reduced, and the end result is value for money and quality assessment in future defence procurements.

According to industry estimates, companies spend anything from 50 per cent to 85 per cent of their software budgets on system maintenance, and of that over 60 per cent goes to adding new functionality rather than simply fixing bugs.

Improved system enhancement was a key issue for one of Switzerland's largest private investment banks.

Solid foundation

"Extensibility was its main criterion for using OO," Howlett explains. "The bank has a team of 40 people constantly extending its current system. They were having difficulty meeting the new requests for functionality and wanted a system which could be easily added to."

The bank decided to rebuild its entire banking system using an open, client/server architecture based on OO technology, and commissioned Logica to help plan the development, which is now being carried out in-house. It is anticipated that OO will form the solid foundation for a system which the bank can rely on for many years.

Logica clients like SMART and Lucas Management Systems are pioneering what is still a new approach to systems development. But their reasons for choosing this route are a response to real business needs, not the desire to innovate. As use of complex distributed systems grows, the signs are that growing numbers of organisations will follow these companies and come to regard OO as a practical necessity rather than a technical novelty.

Candice Goodwin specialises in writing and editing for technology publications and is a former editor of Infomatics