System Architecture Design

What

Documents and figures describing the static layout of the functional blocks, of the system to be.

Block or component diagrams, that shows the functional decomposition into HW and SW blocks respectively

How

General architechture design consists of several steps, that often requires several iterations, untill the optimal architechtre is crafted.

The system architechture and the technical platform, are highly dependant on each other, and again depends on the partition of functionality into HW and SW blocks. Therefore one should expect to iterate between the task in General Architechture design

Ingredients

• System constraints, see [Design Constraint Analysis]
• Availible requirements, in particular concerning
  • performance requirements
  • Interface compatability (i.e. must be able to connect on ethernet, communicate on CAN, have and SD card, run Android OS, etc...)

Process

Partitioning

There is several ways to partition the general blocks from the architectural block diagram into software and hardware parts. In EUDP we recommend to follow the instructions given at Design Partitioning.

Having defined the most effective partitioning prepare the necessary class diagrams to describe the software partition and corresponding diagrams for the hardware.

Why

In order to find the most effective partitioning that at the same time respects the constraints and gives the best value for the customer it is essential to define the constraints for the project. Without proper definition of the constraints the design space is wide, but may not give the customer the best value.

Example

    Issue         Critical       Very Important    Important   Less Important  Notes

Performance                           X                                          1
Usage                X                                                           2
Reliability          X                                                           3
Easy serviceable                                       X                         4
Remote maintenance                    X                                          5
Cost effective                                         X                         6

Notes:

1. The performance is very important.

2. There must not be any difficulties using the system. All kinds of people must be able to use it, there must not be special training! The system-to-be must contain enough electronics to ease and secure the use. It is also preferable to have the possibility to collect different kinds of data from the system-to-be.

3. Errors must not occur. It will be critical if an error shuts down the heating of the house. If the temperature outside is below zero, the house and the system can be damaged if it is not heated. Therefore, the reliability must be high!

4. The system must be easy to repair, if errors occur.

5. All maintenance must be easy, with no or a minimum of disturbances for the user.

6. Many of the parts in the system may already have been developed by other companies. It must be considered how the lowest price is obtained. For all parts of the system-to-be it must be a choice between developing the different parts or buy something similar and redesign if necessary.