computer sciencesoftware engineering slide 1 groups paul simmerlink stephen herbert daniel coming...

Computer Science Software Engineering Slide 1

GroupsPaul SimmerlinkStephen HerbertDaniel ComingOgechi UgwuleboJames King

Jigna J. Bhatt Casey J. PowellBrett HarrisonJonathan WardMichael Vidal

Don MillerJames FryeDavid BrewerOlja MihicCasey Mees

Maggie Lu Reid WebberTaisuke Nagayama Jeff PayneMatasaka Sako

Howard C. WuShana RheaultRichardD.VanHornRodel MangobaSteve Luong

Jason DoddBeifang YiDorothy P. CheungWilliam NelsonWill WoolseyAndrew Rodgers

James Cohen, Judy Rowley, Stan Sexton, Rajashekhar Yakkali, Kazuhito Mori


Project Management tools See the projects web page

Concurrent Versions System (CVS)

Coding standards• Java coding standard document


What have we learned so far? Murphy's Technology Laws1. Logic is a systematic method of coming to the wrong

conclusion with confidence. 2. Whenever a system becomes completely defined, some

damn fool discovers something which either abolishes the system or expands it beyond recognition.

3. Nothing ever gets built on schedule or within budget. 4. All's well that ends. 5. Any given program, when running, is obsolete. 6. To spot the expert, pick the one who predicts the job will

take the longest and cost the most.


What have we learned so far? The first step in software development is

understanding the system to be developed This is requirements analysis Requirements analysis starts with a description of

the system The description is refined into a requirements

document


Requirements document Interaction between engineering, marketing and

clients (domain experts) Iterative Increase understanding of system

• Informal scenarios help understanding and appreciation of system complexity

• Raise questions that need to be answered by domain experts• Propose GUI/UI (more on GUI design later)

Requirements document (formatted formal document)


Do you understand system? Validate your understanding Use Case Centered Design (UCCD)

• Scenarios • Comprehensive, explore all interaction with system

• UML class diagrams• Initial design

• List of primary classes (nouns, properties of primary classes)

• UML use-case diagrams• Compact representation of use of system


Next? Troutman's Laws of Computer Programming 1. Any running program is obsolete. 2. Any planned program costs more and takes longer. 3. Any useful program will have to be changed. 4. Any useless program will have to be documented. 5. The size of a program expands to fill all available memory. 6. The complexity of a program grows until it exceeds the capability of its

maintainers. 7. Any system that relies on computer reliability is unreliable. 8. Any system that relies on human reliability is unreliable. 9. Make it possible for programmers to write programs in English, and

you will find that programmers cannot write in English. 10. Profanity is the one language all programmers know best.


Next Persistence? Inter-process communication? HCI Architecture

• Grouping primary classes• Interfaces

Design Implementation Validation


Persistence LMS Galaxy sleuth GPA


Object Persistence Object persistence seeks to retain object

information on some persistent storage medium as a file or through a DBMS

Object serialization works for situations where all object information can reside in memory at once

Because most commercial DBMSs are relational in contrast to object-oriented, some translation between the object and relational representations must be made


Evaluating Object Persistence Security

• Hacker proof

• Allows reconstruction in face of malicious use

Information growth• Solution still works with increased data volume

Concurrency• Concurrency solution allows for increased users


LMS: Object Persistence

LMS may contain hundreds of thousands of book entries as well as thousands of other library resources

such a volume of data does not permit object streaming

A DBMS is called for to provide• Concurrent access by multiple users• Security enforcement of different access levels for various user

categories• Allow for increased data capacity


What do we want to persist? System state

• ?


LMS Case Study: Relational Representation of Data

Relational TablesBook

Resource List

Patron Address

Patron


Process Architecture

Software systems may consistent of processes interacting over a network

Process architecture lays out the machines (nodes) that will host the processes making up the system

Process architecture determines the behavior of the distributed processes

Deployment diagrams are used to model distributed processes


Sample Deployment Diagram

GameClient

GameClient

GameClient

GameServerInternet


Modeling Interprocess Communication

Deployment diagrams show the distribution of process over multiple nodes but do not indicate how these processes communicate

State machines may be used to model communication between processes

The idea behind using state machines for modeling interprocess communication is that the system enters a new state when messages are exchanged between processes


UML Notation for State Machines

State Name Intermediate State

Initial State

Final State

Trigger State transition with event trigger

State Name

State with substates


Sample State Machine Showing Interprocess Communication

Player Joining Game

Get player name

Select token

{ Client States}

{ Server State}

Communicate remaining tokens

player nameavailable tokens selected

token


Modeling Multiple Threads of Control

Classes that consist of a separate thread of control are modeled as active classes

Active classes are rendered with thick rectangles as shown below

Active classRegular class


Galaxy Sleuth galaxySleuthServer gameBoard playerListener


Design Summary

Create solution for object persistence Develop user interface designs Determine process architecture


Possible Obstacles to Effective Meetings

Poor agendas Dysfunctional communication during the meeting

(silence or domination) Not adhering to the agenda Discussion may not sufficiently focus on meeting

objectives specified by the agenda Team members are not listening to each other

during discussion

computer sciencesoftware engineering slide 1 groups paul simmerlink stephen herbert daniel coming...

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