2. Fundamentals

The aim and objectives of this thesis make obvious, that this thesis is concerned with the analysis and modification of an information system. It can therefore be regarded as a systems engineering project. This chapter collects basic techniques which are necessary for setting up a methodology for the systems engineering approach.

2.1. Systems Engineering

The construction or modification of complex information systems requires structured systems engineering. Teachings on systems engineering can be found for instance in the textbooks [LOCKEMANN et al. (1983)] and [HEINRICH (1976)]. A pragmatic and comprehensive guide for setting up information systems for the management of primary health care systems is provided with [WILSON and SAPANUCHART (1993)]. MOIDU proposes a systems engineering approach in [MOIDU (1993)] which aims at the design of common software application products for primary health care systems. For this thesis a phase scheme for systems engineering of information systems in health care shall be applied as it is taught in [HAUX (1994)].

Systems engineering of information systems in health care according to [HAUX (1994)] is the planning and realization of, and the reporting on projects which aim at the analysis and evaluation of information systems in health care and their components. Systems engineering also includes the selection and introduction of these components. In this sense, systems engineering can be divided into the following phases:

1. Planning of the systems engineering project.
2. Analysis of the information system and its components.
3. Evaluation of the information system and its components.
4. Selection and construction of components for the information system.
5. Introduction and maintenance of the components of the information system.
6. Final reporting on the systems engineering project.

The scope of phases two to four depends on the aim of the project and the planned activities. Each phase can be supplemented with an intermediate report, if needed. The following sections give a more detailed description of the phases.

2.1.1. Project Planning

To keep a systems engineering project within specific boundaries concerning time and contents, it has to be planned ahead in agreement with the client. The resulting project plan should include the following aspects:

• A description of the object of the systems engineering project and the necessity for the project.
• A formulation of foreseeable problems.
• A formulation of the aim of the project.
• A list of objectives or tasks, which have to be completed.
• A description of activities and milestones.

[HAUX (1994)] also describes a method for a systematic deduction of these aspects. However, for this thesis it shall be sufficient to provide the basic structure of a project plan.

2.1.2. Analysis

In [HAUX (1994)], systems analysis is defined as the systematic analysis of information systems and their components. Aim of the systems analysis is the aggregation of information on the existing information system and the health care system in which it is embedded, on a hypothetically ideal information system and on weaknesses of the existing information system. There are several means to gain this information. A selection from those introduced in [HAUX (1994)] is given below:

• Analysis of documents retrieves relevant information from available documents. It is the least invasive and most applied method of systems analysis.
• Observation is a supplementing method to gain information which can not be gained with other methods. Also, observation is not too invasive.
• Inquiry is done directly from involved participants or from external experts. Depending on limitations on time scheduling, availability of informants and the expected results, the method of inquiry has to be selected according to the given situation:
• A written interview usually involves the participation of a selection of informants, with the option to do statistical evaluation on the received responses. It is independent from appointments and not too time exhaustive for the informant.
• Oral interviews enable the interviewer to observe emotions from the respondent and provides the possibility to intervene on unclear answers. Oral interviews can be very time exhaustive, though. There is a variety of different forms of oral interviews, depending on the extend to which the interview is structured.
• A conference or group interview is useful to bring different informants together to resolve contradictions and to discuss complex matters.

It is obvious that systems analysis must include a variety of methods to gain a broad information basis on the information system of concern. However, depending on the available resources and the needed scope and precision of the wanted information only a selection of methods might be applied. Another limiting factor can be found in the extent to which the observed system may be stressed by the systems analysis. In the context of this thesis, qualitative methods for analysis are of a major interest. Section 2.2. "Qualitative Assessment Methods" gives an introduction into qualitative assessment techniques, which are used in the context of primary health care.

2.1.3. Evaluation

During the evaluation of an information system, the results from the systems analysis are matched with previously defined objectives for the information system. In [HAUX (1994)], the following activities are considered typical during systems evaluation:

• Utilization of the results from the systems analysis.
• Formulation of objectives.
• Evaluation of the actual state.
• Suggestion and evaluation of alternatives.
• Consideration of economical factors.

Evaluation of system components can be done quantitatively with the definition of evaluation criteria and a specific weight for each criterion. However, for this thesis a qualitative approach shall be sufficient.

2.1.4. Selection and Construction

Based on the results of the systems analysis and evaluation, components of the information system have to be provided. During this process,

• the results from the systems analysis have to be utilized,
• a requirements specification has to be set up,
• a call for tenders has to be launched and
• the decision for a tender has to be taken.

However, as an alternative to choosing external constructors of information system components, construction can be done by the health care institution itself. Especially for the construction of computer based components there exists a variety of methods. In the context of this thesis a method for systematic data base scheme design is needed, as described in section 2.4. "An Object Oriented Method for Database Scheme Design".

2.1.5. Implementation and Maintenance

After system components have been selected or constructed, they have to be introduced into the information system. Introduction should be done gradually starting in typical application areas. Before a component is introduced, the involved staff has to be trained. At the same time the organizational background for an adequate maintenance of the components has to be provided. For this reason staff must be appointed which is responsible for maintenance. This has to be done on the applicants side as well as on the providers side.

2.1.6. Reporting

During all stages of systems engineering, and particularly after completion, the project has to be accompanied by reporting. Presentations of results should be done preferably by quantitative means using descriptive statistics. However, if quantitative methods are either not possible or not applicable, qualitative methods can also be used. Qualitative presentations can include casuistries or comprised results. Qualitative results have the disadvantage of being difficult to reproduce. Nevertheless it can be a more adequate way for certain topics to use qualtitative descriptions.