Informatics 117: Project in Software System Design
Winter Quarter 2009
Architecture and Module Specifications
February 12, 2009.
design that fully satisfies the requirements for your
application. This deliverable consists of two elements:
a design specification (consisting of an architecture
and module specifications) and an integration test plan.
Your document must specify the correspondence between the
requirements elements and your design. You may show this
correspondence any way you feel is appropriate (e.g., make notations
throughout your document or using a table that cross-references
Developing the software design will undoubtedly reveal inadequacies
in previous documents. Please note these problems and what was done to
Don't forget to include your meeting minutes and performance appraisals
with your document; refer to the syllabus for the complete check-list of
what has to be turned in. As before, make sure that you post your design
documents and your meeting minutes to your team web page.
Keep in mind that key objectives of a design document include:
In addition, keep in mind that a design document should exhibit the
- Develop a coherent representation of software that will satisfy the requirements
- Identify inadequacies in requirements
- Decompose the system into sub-systems that provide related sets of services
- Establish a framework for sub-system control and communication
- Specify modules that can be assigned as coding responsibilities
- Document design decisions and rationale
- Provide a reference tool readable by developers, testers, and maintainers
- Provide a basis for integration and testing
- Complete: everything that is essential is described
- Unambiguous: expressed in a well-defined notation
- Consistent: no mismatched interfaces
- Modifiable: this document will change just like all the others
- Confirmable/testable: you can tell when you've met the
Expand your previous introduction to discuss your specific approaches to the
design of the system and the organization of this document. This
description is essentially just an updated version of the introduction
you included in your previous deliverable.
Expand the understanding section of your previous document. Include brief descriptions
of actions you took to understand each technology studied during
this phase. If you make changes to this section, add text describing why the
change was necessary, and why it more accurately reflects your new understanding.
This section need not be different if your understanding hasn't changed.
This will be an iterative expansion of your previous submission. Update
your project plan to show what you have accomplished so
far. Reassess the project risks as necessary. Expand your task network or work
breakdown structure to include the effort expended to complete this
task, as necessary. Based on the work you have done, revise your estimates on
how much your team can accomplish and deliver.
If you make changes, add text describing why the change was
necessary or why it will improve the ability of your team to accomplish
the work you have proposed.
- Architecture Overview
- Architectural Style
What style of architecture did you adopt? Provide a reference to a
- System Architecture Overview
This is the place for your "one great diagram" that shows how your
system is built. You might want to use more than one diagram, to show,
e.g., some different abstractions of the design (such as a data flow view,
a layers of abstraction view, an object view, or an OS process view) – multiple
diagrams are fine.
- Subsystem Narrative
What each subsystem means
- Major limitations on the current design (if any)
- List of Modules/Objects within your system
- For each module/object, provide a Module Specification
- Definition/Purpose - what it is/does
- Narrative/Comment - how it works
- What are the interfaces or APIs? Visibility?
- Data - What state does it keep (if any)?
- Access - Who has access to the module/object/data?
- Requires – What modules does this module depend upon?
- Constraints - what constraints are there for this object/module? (e.g.
must start first, must be registered with ..., must ....)
- anything else necessary to fully describe the module
- Diagrams you could consider using in providing this specification: UML
class diagrams, event sequence (trace) charts, state transition diagrams,
package diagrams, ...
Integration Test Plan
A test plan capable of demonstrating that the
design meets the requirements. Test
cases should cover each module/object interaction
specified. The test cases can be grouped with the design
entity to which they apply, otherwise a cross reference listing of some
sort should be provided.
- For each test
- Test ID
- Purpose of Test
- Item(s) being tested
- Input specification
- Output specification
- Expected Results or Test Oracle Mechanism
- Test environmental needs or special test procedures
Initial Demonstration Plan
What and how will you demonstrate?
Tracking and Control Mechanisms
Configuration Management: how will your modules/objects be managed?
- SVN? CVS?
- file structure, sub-directories, Makefiles, etc.
- where is your persistent data going to live?
Requirements Cross Reference: what modules/objects satisfy what requirements?
- a table mapping requirement to module/object
Modifications to Prior Documents
If any requirements changed make them explicit. Highlight why the requirement
was changed/added/deleted and by whom (customer, developer, etc.). If your
requirements have not changed, then so state.
Define any "irregular" terms used in the specifications above. This portion
of the document may be written as an extension to the glossary submitted
with the requirements, or may be a separate document that only defines
terms local to the design activity.
This section is reserved for any additional documentation developed
during this phase of the project. Specifically, if during the course of
developing the architecture your understanding of the various
technologies involved in the project changed, or you discovered items
that were not documented but which are important, include that
information here. Also list here the major background sources that you used during
this phase or any that you plan to use during the remainder of the
project. This includes references to similar systems and/or
See the syllabus for dates. Each team should prepare a 15 minute presentation.
Your presentation should include
- Some context for your project (very brief!);
- Current state of your project plan and comparison to the previous version
of the plan;
- Highlights of your design including
- an overview of your architecture (this should comprise the bulk
of your presentation) – the "one great diagram"
- one or more key module/object specifications;
- [As needed] Modifications to your requirements that arose as a result
of your design process;
- Overview of your integration test plan.