This assignment is to be performed individually. Informal discussions with classmates are acceptable; however, all submitted work is to be your individual work.

Assignments are to be submitted in the ELEC 372 assignment drop box, located outside Goodwin 235, by Friday April 6 at 1:00 PM. A solution will be posted shortly after the assignments are collected, so we will not be able to accept late assignments. Note that printers often become backed up shortly before assignment submission deadlines - please take this into account in your planning.

Note: the answers to the questions in this assignment DO NOT require any code to be written. The answers are based on identifying and describing large components in your design, and do not involve a detailed code-level design. A "high-level" architectural design is produced during the first iteration of design drawn from the requirement specifications and should not contain any code-level details.

1. The Mary Shaw paper "Some Patterns for Software Architecture" describes a number of software architectural styles identified from industry applications: http://www.cs.cmu.edu/afs/cs/project/vit/www/paper_abstracts/PLoP95.html
   This paper provides an alternative source to the readings assigned from Bass/Clements/Kazman.

   1. In the table below, give an example of a type of application that would be best designed using the given architectural style. (You may draw from the applications presented in class.) For each case, consider the quality attributes of running time, verifiability, and reusability (i.e., replacing existing components, portability, adding new components) and provide brief comments on how those qualities are affected by the architectural style.

Architectural Style	Your Example	Comments on Reusability	Comments on Running Time	Comments on Verifiability
Layered
Data Centred
Event Driven

1. Suppose you have three components, A, B, C, that you are trying to compose into a system as shown in figure 2 (below). One of the commonest problems when composing components is the fact that often they do not agree on how the data should be represented. Suppose you have the following characteristics for your system:

   1. component A is written in-house and you have the source for component A
   2. you don't have the source for components B and C
   3. the format of the output from A follows a company wide standard
   4. the output from B and C are not in the company standard format
   5. the input to C is in the company standard format
   6. component A may be replaced in the future by a third-party component
   7. all three components work independently
   8. the final output from the system has to be in the company standard format
   9. the company standard format may change in the future

Data Flow	Adaptation recommended by you (if one required)	Reason for this choice
Input to C
Output from C
Input to A
Output from A
Input to B
Output from B

1. (Courtesy of Maj.Greg Phillips, RMC) In response to complaints about a lack of intelligence analysis capability, the Department of National Defence initiates a multi-billion dollar project called RABID CALF: the Really Astoundingly Big Intelligence Data Collection and AnaLysis Facility. By means of a highly structured requirements elicitation and validation process (performed by a bored clerk on a cocktail napkin over lunch) the following set of critical information system requirements are identified:

• Intelligence information data elements will be received in three formats: high resolution reconnaissance photographs, voice recordings, and text-based field reports.
• Each received data element must be automatically preprocessed (e.g., the voice recordings will be filtered to remove background noise). Each data format will require a different form of preprocessing.
• Each data element must be manually validated and have "meta-data" attached to it. This might include, for example, keywords, locations, times and dates added to reconnaissance photographs.
• All data elements and associated meta-data are to be retained in an online intelligence library.
• Due to the volume of data, much of the analysis will be performed by "intelligent" software. There will be a large number of software agents constantly analysing the data and adding their results to the online library. The number of agent types is expected to increase over time as new software is developed. Initial software agent types are:
  • image feature recognizers, which will detect and identify items of interest in reconnaissance photographs;
  • transcribers, which will produce textual versions of voice recordings;
  • collators, which will identify and group related images, voice recordings, and field reports based on meta-data, contents, and the results of other analyses; and
  • trend analysers, which will identify significant trends over time or space.
• A separate interface will allow human intelligence analysts to browse and search the library. It will direct their attention towards elements or groups of elements identified as interesting by the software agents. Based on their analyses, the human analysts may add further information to the library.
• Periodically, a high-level summary report must be generated for the Department's senior intelligence officer, the Director Of Stuff You DOn't talk about (DOSYDO).

After you make the mistake of beating her at golf one afternoon, your boss tasks you with designing a high-level architecture for RABID CALF's information system.

1. Identify an appropriate architectural style to use as the core architecture for the system. Justify your choice. If there are identifiable subsystems with other architectural styles, explain what these are. (This explanation should be around a half page in length.)
   
2. Produce a high level architectural diagram for the RABID CALF information system. It must include all components necessary to carry out the functions indicated in the requirements. Clearly label each component and connector in such a way that it is clear what role the component or connector is playing. See figure 1 for an explanation of the symbols to be used in your diagram.