Kevin Corker San Jose State University 2/10/05

1. Lecture 4 Conceptual System Design & Introduction to Functional Allocation ISE 222 Spring 2005Notes & Course Materials www.engr.sjsu.edu/kcorkerKevin.Corker@sjsu.edu Kevin Corker San Jose State University 2/10/05

2. Agenda • Review System ID Scope and Bound Process • Complete the IDEF and action based costing • Preliminary Design Review Process • Introduction to Human Factors • Review Homework (with individuals and teams)

3. Identification of Need • Gap • New Techniques • New System Requirements added • System Requirements Change Priority • Political Views Shift • … • Involve the customer– unless the customer has changed as well

4. System Definition Matrix:National Identity Confirmation Process Scope Bound Needs Objt Criteria Params Var Constrnt

5. National Identity Confirmation ProcessNeeds • Ability to determine the identity of individuals in this country • quickly • at any place or time • to assure accuracy of identity information • to assure privacy and security of individual’s identity

6. To institute a national identification process Portable and reliable To provide appropriate authorities with information: Name Address Visa/citizenship status Criminal Information Health Information Contact and NOK (next of kin) Information Tracking??? … Able to be carried on or in person whgt,< 4 oz Volume < 2 cubic centimeters Able to be accessed by pedestrian, automotive, or desk based systems Able to link to national information sources Wireless access range Access queue management Bandwidth National Identity Confirmation ProcessObjectives Criteria Parameters

7. To provide appropriate authorities with information:Objectives • Easy access • Time to access • Encumbrance fro access • Voluntary or not access process • Validation of data…

8. To secure ID from tampering or duplication To secure ID from un authorized access To keep all information current Sealed no remote access Access limited Update Rate compatible with National Standards Update per week?? National Identity Confirmation ProcessObjectives Criteria

9. Alternatives • A1: Hand carried ID with federal specification and on board storage • A2: Bio-referenced ID for identity with link to data store for other information • A3: Implanted RF-ID with data on board and with link to data store for other information

10. Secure All Environ access Lightweight Accessible for mods

11. Implanted Hand Held Bio-ID Asynchronous & Constant Update Full Cross Index Wireless Data Base 1 Privacy Public 1 Security 2 Accuracy 3 Convenience Access Ease 1 Authorities Info Density 11 2 Info currency 3 Priority

12. Functional Analysis and Allocation

13. Action Reference Framework • To (do something) to (something) somehow • Action , object, modifier • Used to describe a process Functional Decomposition is to develop a description of what the system must do – not necessarily tied to how the system must do it.

14. Action/Task Action/Task Action/Task Action/Task Action/Task Action/Task Functional Flow Block Diagram Boolean Operator

15. Hierarchic Structure for Decomposition • Sub Functions operate on input/output consistent with the higher levels of the hierarchy • Models the flow of data or objects in a system

16. ICOM Control Activity Inputs Outputs Mechanism

17. Method of Analysis • Shows roles of information and materials with respect to activity • Each ICOM represents an activity or business step that can be broken down • Inputs: information/material used to produce activity output • Controls: Constraints on an activity • Mechanisms: That perform processing or provide energy to the activity (people or machines as mechanisms) • Output: The product of the activity

18. Context Diagram Control Activity Inputs Outputs A0 : Purpose : Viewpoint Mechanism

19. Target OOB Procedures Procedures orders Sight & Designate Target Expected Result Ordinance Inventory Select & Prepare Ordinance Guidance Equip Deliver Ordinance Access Damage Captain Automation Gunner Gunner Automation Captain

20. Steps in Functional Decomposition • Develop Context Diagram of Full System • Decompose System to Sub-elements (ICOMS for all) • Define Business Rule/Model • AS-Is the descriptive scenario • To-Be the future business or process model • Cost Analysis • Analysis of activities, • Gather costs, • Trace costs to activities, • Establish output measures, • Analyze costs

24. Steps/Perspectives for System EngineeringAnalysis • System Analysis • Identification of the impacts and consequences of alternative approaches to system solution • Identification of the quality, market, reliability, cost, effectiveness, benefits, longevity, aesthetics… of alternative system solutions • Iterative Refinement of Alternatives • Sensitivity Analysis and Parameter Identification

25. Supportability • Inherent Characteristics of system design & installation that enable efficient maintenance and support of the system • Prime Elements: • Design Reliability Quality and Maintenance • Maintenance Infrastructure • Maintenance • Training • Supply chain support • Equipment • Packaging • Faculties • Technical Data

26. Preliminary Design Review (due 2/17) • Identify design & alternatives (at least 2) • for functional capability • support reliability • allow for maintainability • Usability & safety • Support for service

27. Human Factors Introduction

28. Environment Operator Machine/System Organization Roles & Responsibilities Training Communication Capabilities Modulating Variables Perception Cognition Response Controls Tasks Allocation Feedback Time Info Temp Noise Illumination Effectors Performance Capabilities Displays Performance Affordances Performance Requirements Performance Limitations Systems Engineering Approach to HCI Features Automation

29. Motor Behavior Theory for Guidance in Design and Selection of Input Devices • Purpose to match a physical output on the part of a user to a signal that is recognizable by a system. • Bandwidth: range of expression • Dynamics: speed of response • Dimensionality: physical and temporal relations that the input device can support • Affordance: appropriate and expected response: in use and in feedback • E.g. button click or highlight changes in isotonic devices • Discrete entry devices and Continuous entry devices • Physical limits: • Ergonomic consideration • Environmental impacts: vibration, clothing restrictions, noise and etc. • Physical Measurement, information theory and neuromotor accuracy

30. Human Performance Models • What are they? • Expressions of relationships that either describe (descriptive) or predict (normative) human behavior across a range of environments or contexts • Specifics: • Perceptual Models, Information Processing Models, Motor Behavior Models, Decision Models, Framework Models, Unified Models….

31. Working Memory 200 ms 1500 7-17 letters 5 letters • LTM • 70 ms X Cognate 70 msec /cycle Motor Response 70 msec Percept: 100 msec

32. INFORMATION MEASUREMENT • Information : property of messages and data or other evidence that reduces one’s uncertainty about the true state of the world. • Let x represent a hypothesis about the state of the world • Let y represent the observation that has a relation to x • I(x:y) is the relation of the observation to the state of the world • I(x:y) should be a function of the prior probability of x before y is observed and the posterior probability of x after y was observed: F[ p(x), p(x|y)] = log2 P(x|y)/p(x)

33. Information Qualification Loss Input Output Noise

34. Information Qualification What Effect does redundancy have on total information transmission? H Loss H(x) H(y) T(x,y) Input Output Noise C (bits/sec) = bandwidth log2 (signal/noise+1)

35. H(x) = Spi log2 pi H(x) = Sp(xi)[log2(1/p(xi))] For equi-probable events For differently probable events H(x) H(x|y) H(y|x) H(y)

36. Hick’s Law Reaction Time RT = a + b H(x) where H(x) = log2(n) .8 sec .6 sec .4 sec .2 sec 1 2 3 4 5 6 7 8 Bits 1 2 2.58 3

37. Fitts LawMovement Time = a+b(Id) Id = log2 [2*amplitude/(tolerance)] Movement time .8 .6 .4 .2 Id 1 2 3 4 5 6 7