1. Copyright  2003 by Dr. Gallimore, Wright State University Department of Biomedical, Industrial Engineering & Human Factors Engineering Human Aspects of Systems Design

2. Copyright  2001 by Dr. Gallimore, Wright State University Department of Biomedical, Human Factors, & Industrial Engineering Introduction Designing the human element into a system is paramount to its success One human error could bring a major catastrophe. Examples –3 Mile Island –Jack Hammers

3. Copyright  2001 by Dr. Gallimore, Wright State University Department of Biomedical, Human Factors, & Industrial Engineering Characteristics of a System Design Process Molecularization Requirements of the system define options –Such as height required for legible picture on a computer screen Some Unknowns are addressed during the design process. –These are due to limitation and processes of building that are unsure –E.g. the budget changing, new members of the team, innovative ways of manufacturing, or how part A will interface with part B.

4. Copyright  2001 by Dr. Gallimore, Wright State University Department of Biomedical, Human Factors, & Industrial Engineering Characteristics of a System Design Process Transformation –Physical requirements to behavioral implications to physical manifestations. Time and Cost Constraints Iterative Cycle (Design, test, redesign, test…) Competition between groups within the design team –Between sales, administration, manufacturing, HFE, etc. –More money/members/power = more influence

5. Copyright  2001 by Dr. Gallimore, Wright State University Department of Biomedical, Human Factors, & Industrial Engineering Characteristics of a System Design Process Relevance to the design –Must convince others of the importance of your contribution in order to get it accepted.

6. Copyright  2001 by Dr. Gallimore, Wright State University Department of Biomedical, Human Factors, & Industrial Engineering Six Major Stages in the Design Process 1.Determine the objectives and principles of the process. Purpose of system General terms feed into System Performance Specifications Details what system is to do in order to meet objectives Defines constraints Bailey (1982) sted that there are two HF activities appropriate at stage 1

7. Copyright  2001 by Dr. Gallimore, Wright State University Department of Biomedical, Human Factors, & Industrial Engineering Six Major Stages in the Design Process Bailey (1982) sted that there are two HF activities appropriate at stage 1 –Identify all users of system –Indentify the activity related needs of users which the system will be responsible for. Example Oven, used by many types of people, families, single person, elderly, etc. Children may try and use door as a stool.

8. Copyright  2001 by Dr. Gallimore, Wright State University Department of Biomedical, Human Factors, & Industrial Engineering Six Major Stages in the Design Process 1.Definition of the System Define functions of the system to meet the performance criteria This is general at this stage. Not assigned to human or machine Functions could be short or long, simple or complex, Aid at this stage is functional flow diagrams (figure 22- 2 in book) List function snot the way they are carried out.

9. Copyright  2001 by Dr. Gallimore, Wright State University Department of Biomedical, Human Factors, & Industrial Engineering Six Major Stages in the Design Process 3.Basic Design –Allocation of functions to human, computer, and software –Sometimes this is considered by economic considerations or the superiority of one over another –There are gray areas, where both human and machine could perform job equally well.

10. Copyright  2001 by Dr. Gallimore, Wright State University Department of Biomedical, Human Factors, & Industrial Engineering Six Major Stages in the Design Process Guidelines for Function Allocation HUMANS reason inductively sense unusual events develop new solutions MACHINES monitor for prespecified events store and retrieve coded info exert considerable force perform repetitive activities reliably

11. Copyright  2001 by Dr. Gallimore, Wright State University Department of Biomedical, Human Factors, & Industrial Engineering Six Major Stages in the Design Process Guidelines for Function Allocation –1. Mandatory Allocation Allocate functions based on system requirments, hostile environments, safety considerations, or legal and labor constraints These allocations made first –2. Balance of Value (figure 22-3 in book) Can the machine or human do it better –3. Utilitarian and cost-based allocation Functions may be allocated to humans simply because they are present Which costs less?

12. Copyright  2001 by Dr. Gallimore, Wright State University Department of Biomedical, Human Factors, & Industrial Engineering Six Major Stages in the Design Process Guidelines for Function Allocation (cont) –4. Affective and cognitive support allocations Affective support – the emotional requirements of humans, such as needing challenging work and feeling personally secure Cognitive support – the human need for the information to be relevant so that they can be ready to make decisions when required.

13. Copyright  2001 by Dr. Gallimore, Wright State University Department of Biomedical, Human Factors, & Industrial Engineering Six Major Stages in the Design Process 4.Interface Design This stage is performed concurrently with Stage 5 only after the proper allocations of functions have taken place This stage deals with designing: Spaces Displays Controls Computer dialogs Etc.

14. Copyright  2001 by Dr. Gallimore, Wright State University Department of Biomedical, Human Factors, & Industrial Engineering Six Major Stages in the Design Process 4.Interface Design (cont) Primary activities of the HFE Team at this stage: Gather and interpret HF and human performance data Conduct human performance studies Conduct attribute evaluations of suggested designs

15. Copyright  2001 by Dr. Gallimore, Wright State University Department of Biomedical, Human Factors, & Industrial Engineering Six Major Stages in the Design Process 5.Facilitator Design Plan for materials that will promote acceptable human performance Examples : instructional materials, performance aids, training devices and programs, selection Guidelines for Instruction Manuals Avoid information overload Use only concrete information Remember that learning will come from doing Users want minimal hassle in setting up

16. Copyright  2001 by Dr. Gallimore, Wright State University Department of Biomedical, Human Factors, & Industrial Engineering Six Major Stages in the Design Process 6.Testing and Evaluation Evaluation – the measurement of system development products (including hardware, procedures, and personnel) to verify that they will do what they are supposed to do. Human factors evaluation – the evaluation of these products to ensure the adequacy of attributes that have implications for human performance. Special considerations for HF evaluations Subjects Criteria Experimental procedures and controls Research setting

17. Copyright  2001 by Dr. Gallimore, Wright State University Department of Biomedical, Human Factors, & Industrial Engineering Six Major Stages in the Design Process

18. Copyright  2001 by Dr. Gallimore, Wright State University Department of Biomedical, Human Factors, & Industrial Engineering Six Major Stages in the Design Process