Humanities

Lecture (8)

The Engineering Approach to Problem Solving

Problem Solution

Real – world problems are often unstructured and open – ended

A problem may have multiple solutions Each solution has many advantages and

disadvantagesThe preferred solution is that best meet the

needs and desires of an employer, a client, or the public.

The Nature of Engineering Design

• Engineering work often involves planning and analysis in the initial stages, but the essence of engineering problem solving is design.

• Engineering design is as varied as the engineering profession and as board as the problems facing humankind.

• Engineering design: is to conceive, imagine, devise and plan a device, a structure, a process, or a system that will benefit people.

Team Work• Design of large projects needs to be carried out by

many engineering teams of different engineering specialists.

• Team work: “is the work done by several associates with each doing a part, but all subordinating personal prominence to the efficiency of the whole ’’

• Team work can lead to better decisions, products, or services.

• A disadvantage of the team work is the “social loafing” i.e. an individual’s doing less work than what he would normally do working individually.

Engineering Design Phases

1- Identification of the problem.2- Gathering needed information.3- Searching for creative solutions.4- Stepping from ideation to preliminary

designs.5- Evaluation and selecting of preferred

solution.6- Preparation of the reports, plans, and

specifications.7- Implementation of the design.

1 - Identification of the Problem• An incorrect definition of the problem will make the

engineer to waste time and may lead to inappropriate solution.

• It is important that the stated needs be real needs

• If it is a product that is being designed, a preliminary market analysis will be essential

• The problem shouldn’t be unnecessary constrained

• If too many constraints are placed on the problem, this may cause its solution extremely difficult or impossible

2 – Gathering Needed Data• Data or information will depend on the type

of the problem to be solved

• Data could be physical measurements, maps, results of laboratory experiments, patents, results of opinion surveys

• Engineers shall undertaken literature search to learn what others have learned about related problems

Engineers may visit technical libraries, study text books, journal articles, and manufacturer‘s catalogs

If the engineer is employed by a large corporation or a public agency, it will be useful to search old files and interview other colleagues who dealt with similar problems

3- Searching for Creative Solutions

Several operational techniques can be used to help a group to produce original ideas:- Brainstorming: - group of usually 6-12 people who introduce ideas to solve a specific problem - They generate as many ideas as possible- They may combine or improve on ideas of others-Brainstorming sessions usually last not longer than one hour.

- Checklists:Checklists include various points of design possibilities. For example if it is supposed to improve a certain device the checklist may include ( ways the device could be rearranged, ways the device could be magnified, ways the device could be put to other uses, . . )- Attribute Listing:List all attributes of product / object: Ex: Color, Material, Size, Weight, . . . Think of all ideas to improve each attribute separately

4 - Stepping From Ideation To Preliminary DesignsThis is the heart of the design process.Possible solutions and ideas to be carefully

evaluated.Engineers often rely on models to facilitate

the design process.The model is “ any simplified description of

an engineering system or process that can be used in the analysis or design “

Three types of models:a - Analytical or mathematical models A mathematical model consists of one or group

of equations that represent a physical system.EX: s = k g h Where : s = lateral earth pressure

g = soil weight h = height of soil

b – Simulation ModelsWhen studying complex systems, engineers use computer simulation models ( 2D or 3D )

c – Physical ModelsHave been used for many years in the fields of structure design, hydraulics, hydrodynamics, aerodynamics

5- Evaluation and Selection of Preferred SolutionFeedback, modifications, and evaluation may

occur repetitively as the device or system evolves from concept to final design.

If we deal with a product : safety, cost, reliability, and consumer acceptability are of paramount importance.

Economic studies can be used to: (determine the feasibility of a project, compare alternate designs, priority of construction of a group of projects )

6- Preparation of Reports, Plans, and SpecificationsThe final design must be presented ( to those

who must approve it ), in the form of an engineering report , a set of plans and specifications.

7- Implementation of the Design

To the design engineer , it is the most satisfying phase of all

Learning From Failures

Engineering failures may be attributed to:1- Mistakes made by careless designers.2- Imperfections in building or manufacturing

materials.3- Careless workmanship by technicians or

craftsmen who implement the design.4- Poor communications between the

managers, engineers, technicians, and craftsmen who produce or construct the design.

Case StudyKansas in 1981: Two walkways in Hyatt

Regency Hotel collapsed. 114 people killed and 185 injured.

A connection detail was changed at the site by the contractor without consulting the designer.