Problem: The iLearn system is a digital learning environment used to support learning in schools with students from age 4 to 18. It is intended to replace an existing system (Glow) that was specially built for the purpose and which includes its own applications for e-mail, etc. Glow was a closed system where it was impossible for users to introduce their own applications. It became less and less used as the facilities in freely available systems were far superior to those offered in the closed system.
One of the most important requirements for the iLearn system was that it should be an open system that could easily accommodate new features and existing services. We aimed to achieve this by designing the system so that everything was a service and that, with appropriate permissions, users could replace pre-specified services with their own service version. This approach also allowed us to deal with the complexity of integrating with existing network management systems (local areas had different policies on which web sites could be visited by school students, depending on age and content) and school administration systems. By creating a service interface to these systems, different underlying systems could be accommodated.
There are three types of service in the system:
- Utility services that provide basic application-independent functionality and which may be used by other services in the system. Utility services are usually developed or adapted specifically for this system.
- Application services that provide specific applications such as email, conferencing, photo sharing etc. and access to specific educational content such as scientific films or historical resources. Application services are external services that are either specifically purchased for the system or are available freely over the Internet.
- Configuration services that are used to adapt the environment with a specific set of application services and do define how services are shared between students, teachers and their parents.
A number of different software engineering methods including viewpoint oriented requirements, use-cases, and UML modeling was used but, all a failed. The only approach which worked was user stories, which people without a technical background could easily relate to. The main reasons why these software engineering methods failed were firstly (and most importantly) users did not care about the system requirements and did not have time to interact with the development team. Secondly, stakeholders simply did not understand the terminology or approaches used - terms such as use-case simply made no sense to them.
The first issue that of disengaged users, is one that is increasingly common. There is so much cheap or free software available, that users can develop their own way of working and simply do not see the point of corporate system. In some respects, this is because they do not understand issues such as security but in others, the problem is that the benefits of corporate system are not for the end-user but for the organization. It is perfectly reasonable for end-users not to wish to take time out from their normal job to discuss new systems which offer them no real benefits. Consequently, requirements engineering for systems that have a diverse user base is becoming increasingly difficult.
Based on the case study given:-
1. What assumptions underlie the idea that a system should be organized as a core system that implements the essential requirements, plus extensions that implement additional functionality? Can you think of systems where this model would be appropriate?
2. Discussions of the use of user stories as a means of deriving system requirements. User stories were extensively used here by the development team to get an overall picture of how the system might be used.
3. Based on the lecture you learn about architecture concepts, discuss where the layered architecture of the system features and elements in the architecture are implemented as replaceable services.
4. In general discussions of systems of systems. This was designed as a system of systems with the digital learning system interacting with other network management and administrative systems.
5. In discussions of sociotechnical systems and complexity. In this system, the technical complexity is relatively low but the governance complexity is very high. As a conclusion what is your opinion about this.