The Following Basic Definitions and Concepts Were Probably Covered in Secondary School

The Following Basic Definitions and Concepts Were Probably Covered in Secondary School

SYS364DEFINITIONS AND CONCEPTS REVIEW

The following basic definitions and concepts were probably covered in secondary school or during your first semester here, however, it will be helpful if we all share the same vocabulary, and they are therefore memory work.

 means "is defined as"

Data  a collection of facts and/or opinions

Information  data which has been processed, either to make it more useful to a human (informative) or to put it in

better shape (format) for further processing

Process  operation performed on data to make it either more informative or better format,

e.g.: calculation, sorting (sequence), sorting (categories), graphing, highlighting, comparing, averaging, summarizing, merging, collating, ...

IP  Information ProcessingIS  Information SystemsIT  Information Technology

IP System  an alternating network of processes (the nodes) and data (the arcs)

Process may be either a program or a procedure

Program  an ordered list of instructions to a computer to perform some IP task (usually created by a programmer)

Procedure  an ordered list of instructions to a person to perform some IP task (usually written by a systems analyst)

Note that there are always many more procedures in most computer-based systems than programs! Some procedures may be "buried" within programs, as Help screens or other forms of instructions.

CYCLIC METHODOLOGIES WITH WHICH WE ARE FAMILIAR

SYS364DEFINITIONS AND CONCEPTS REVIEW

SYSTEM DEVELOPMENT LIFE CYCLE

Preliminary Investigation

(Problem Definition)

Analysis (Feasibility Study)

Design

Construction

Implementation

SYSTEM DESIGN

Specify system components

Design output

Design input

Design data stores

Design controls

Design processes

PROGRAM CREATION

Obtain specifications

Obtain sample I/O

Refine specifications

Dream up algorithm

Record algorithm

Develop Test Data

Test Algorithm

Code program

Compile and fix syntax errors

Debug program and fix logic errors

SYS364DEFINITIONS AND CONCEPTS REVIEW

Note that these methodologies are not "linear", requiring that each step be done in this sequence and only in this sequence. Rather, it is anticipated that completing a step may require revisiting/revising prior steps. However, they promise that less "wheel spinning" will be required if the steps are done in the prescribed sequence.

SYS364 A,B,C 001DEFINITIONS AND CONCEPTS REVIEW

Design is an early stage in the construction of many things: buildings, furniture, bridges, clothing, gardens... The following is a "universal" process for accomplishing any type of design. While not formally part of the SYS364 subject, it is helpful for many of the design challenges which are part of this subject.

The Design Process is a cyclic process. It has five phases:

1.Acceptance

2.Exploration

3.Ideation

4.Selection

5.Implementation

Like all cyclic methodologies, some prematurity is inevitable, and some cycling back probable. However, there are two warnings about getting out of step:

•Acceptance must come first•Premature Selection impedes Exploration and Ideation

This methodology can be used for problem solving as well as for design.

Its greatest strength is that it yields good designs (or solutions) as well as assurance that the chosen design is the best available design for the given circumstances.

Acceptance means believing that you personally can accomplish this design and gets you started. Both motivation and accomplishment are involved, and are mutually supportive. The "symptoms" that a challenge has been accepted are these: the project has a name, it has files (paper folders and/or computer files), a date/time has been set for completion of the design, time has been allocated (set aside) for doing the work, a journal has been set up to record progress.

Exploration could be described as three phases, but they interlock so much that it is better to treat it as a single phase which includes Research, Analysis, and Definition. Exploration is complete, and Ideation can begin, when the following Definitions have been documented: objectives for the design and their priorities, criteria by which these objectives can be measured, the nature of designs for similar products and related products, the entire life cycle of the product, a solid profile of the major users of the product, sketchy profiles of other users of the product, the constraints on the product and on the project, the resources available to the project to create the product.

Ideation (the dreaming up of ideas) is not the most "creative" phase, nor does it require "talent". It usually involves "lateral" (right brain) thinking as well as the more disciplined "linear" thinking reinforced by our school systems. The emphasis for this phase is on recording a huge quantity of ideas (quality comes later). Many techniques are useful for ideation, including brainstorming, word games, imitation, play, ... immersion and incubation, working top-down, working bottom-up, working middle-out. There is no "symptom" for the end of Ideation, because it can continue indefinitely! Other people's ideas are fair game during this phase of design.

Selection can only proceed when there is sufficient bulk in the ideation files! This phase is just as creative as Ideation, but it is more disciplined. It involves evaluating each idea on the basis of the criteria recorded during Exploration. It usually involves selecting partial ideas, and reverting to Ideation to bridge them. The symptom for completion of Selection is the chosen design and the reasons for preferring it to all others.

Implementation of a design is not construction. It is simply preparing specifications for construction. The phase is complete when the design is ready to be "built".

Post-Implementation activities involved in Design (or problem solving) involve preparing the specifications for the constructors, plus re-filing all the material collected during Acceptance, Exploration, Ideation, and Selection. Project history may be useful for estimating subsequent design projects. Ideas may be useful for other projects. Research and Analysis materials should be re-filed for easier access on other projects.

The great success of this methodology is that you not only know you have built a good design, you know why it is the best possible design!