Ivan
Modular Decomposition Style
MHC –PMS
Local
MHC – PMS Server
Patient Database
MHC –PMS
Local
MHC –PMS
Local
1. It is an efficient way to share large amounts of data. There is no need to transmit data explicitly from one sub-system to another.
2. However, sub-systems must agree on the repository data model. Inevitably, this is a compromise between the specific needs of each tool. Performance may be adversely affected by this compromise. It may be difficult or impossible to integrate new sub-systems if their data models do not fit the agreed schema.
3. Sub-systems that produce data need not be concerned with how that data is used by other sub-systems.
4. However, evolution may be difficult as a large volume of information is generated according to an agreed data model. Translating this to a new model will certainly be expensive; it may be difficult or even impossible.
5. Activities such as backup, security, access control and recovery from error are centralized. They are the responsibility of the repository manager. Tools can focus on their principal function rather than be concerned with these issues.
6. However, different sub-systems may have different requirements for security, recovery and backup policies. The repository model forces the same policy on all sub-systems.
SYSTEM DESIGN
SYSTEM GOALS * The system should be easy to use by experienced controllers and should be organised in such a way that user errors are minimised. * The system should be used by the staff to register the patients appearing for the first time at the
MHC –PMS
Local
MHC – PMS Server
Patient Database
MHC –PMS
Local
MHC –PMS
Local
1. It is an efficient way to share large amounts of data. There is no need to transmit data explicitly from one sub-system to another.
2. However, sub-systems must agree on the repository data model. Inevitably, this is a compromise between the specific needs of each tool. Performance may be adversely affected by this compromise. It may be difficult or impossible to integrate new sub-systems if their data models do not fit the agreed schema.
3. Sub-systems that produce data need not be concerned with how that data is used by other sub-systems.
4. However, evolution may be difficult as a large volume of information is generated according to an agreed data model. Translating this to a new model will certainly be expensive; it may be difficult or even impossible.
5. Activities such as backup, security, access control and recovery from error are centralized. They are the responsibility of the repository manager. Tools can focus on their principal function rather than be concerned with these issues.
6. However, different sub-systems may have different requirements for security, recovery and backup policies. The repository model forces the same policy on all sub-systems.
SYSTEM DESIGN
SYSTEM GOALS * The system should be easy to use by experienced controllers and should be organised in such a way that user errors are minimised. * The system should be used by the staff to register the patients appearing for the first time at the