Arthur C. Jones Thesis Committee Mike McNeese (thesis advisor) - - PDF document

THE INFORMATION-TECHNOLOGY- PEOPLE ABSTRACTION HIERARCHY: A TOOL FOR COMPLEX INFORMATION SYSTEM DESIGN

Arthur C. Jones

Thesis Defense Presentation

Thesis Committee

• Mike McNeese (thesis advisor)
• Steve Sawyer
• Dan Lorence

Abstract

This work presents a general model for developing the requirements and constraints for the construction of information systems. The model is based upon Rasmussen’s [1986] abstraction hierarchy model, but substitutes the elements of information, technology, and people as peers in place of the traditional whole-part hierarchical decomposition. The resulting I-T-P Abstraction Hierarchy is shown to have utility for information systems engineers and is demonstrated by applying the model to the design of a system for emergency services dispatch operations.

Who is this guy?

• Long time computer enthusiast (hardware,

networking, programming, database designer)

• Paramedic – instructor (various

environments)

• IST student

Outline of presentation

• Some preliminary information, definitions, etc.
• Abstraction Hierarchy Models
• The Information-Technology-People trichotomy
• My model, the general I-T-P AH
• Demonstration

– WDA – Domain-specific model – Implications – Prototype construction

• Conclusion & Future Work

What are “Information Systems”

• Information System = coordinated activity

involving information, technology, people.

• I-T-P Trichotomy exists throughout

literature, but using different names.

What are “Critical Incidents”

• The term “critical incident” as applied here

is an extension of Flanagan’s [1954] concept: “…defined as extreme behavior, either outstandingly effective or ineffective with respect to attaining the general aims

• f the activity.” The extension applied to

this definition is in consideration of the response to unforeseen circumstances, and an acknowledgement that some circumstances can not be foreseen.

Critical Incident Information Management Systems

• Importance
• Complexity
• Potential for failure
• Results of failure
• Motivation for better systems

What is “better?”

• “Better” ? more complex system

– Trauma shears – The “splashback” problem [Vicente 2004]

• “Better” = able to adapt

– Requires a more complex design process

Abstraction Hierarchy Models

Physical Form Physical Function Generalized Function Abstract Function Functional Purpose Means – Ends Abstraction Hierarchy Component Subassembly Functional Unit Sub-System Total System Whole-Part Structural Decomposition Hierarchy

Most “concrete” form Representation of physical processes of the system Concept over implementation Causal network, the flow through the system Most abstract form; overall reason for the system

Abstraction Hierarchy Models

• From Rasmussen [1986]
• Abstraction hierarchy along vertical axis

– Choice of layers can vary depending on domain and approach

• Structural decomposition hierarchy (“whole-

part”) along horizontal axis

– Choice of labels can vary here as well

• Why-What-How relationships between strata
• Each layer is a complete representation of the

same system

Abstraction Hierarchy Models

Configuration and weight, size, “style” and color Physical Form Mechanical drum drive; pump and valve function; electric/gas heating circuit Physical Function Washing, draining, drying, heating, temperature control Generalized Function Energy, water, and detergent flow topology Abstract Function Washing specifications; Energy Waste requirements Functional Purpose Means – Ends Abstraction Hierarchy Component Subassembly Functional Unit Sub-System Total System Whole-Part Structural Decomposition Hierarchy

Abstraction Hierarchy Models

• Serve as models for Work Domain

Analysis

• Cell contents are objects (nouns) which

represent the system (the work domain)

• Task analysis can be mapped onto AH

models, as tasks take place within a work domain, but task analysis can not be used to complete the model.

Ecological Interface Design (EID)

• From Rasmussen and Vicente [1994]
• Ecological = natural = uncontrolled.
• Contrasted with intentional (well defined)

systems.

• Uses AH’s why-what-how relationships to define

human-computer interaction needs and constraints.

• Examples applied to nuclear power plant

monitoring and control, manufacturing plants, etc.

Information, Technology, and People

• Part of the foundational philosophy of the School of IST.
• Sawyer, S. & Chen, T.; 2002; Conceptualizing Information

Technology and Studying Information Systems: Trends and Issues; in Myers, M. & Wynn, E. & DeGross, J. (Eds.) Global and Organizational Discourse About Information Technology,London: Kluwer, 109-131

• Vicente [2004]: “soft technologies”
• Xia & Lee [2004]: “organizational factors”
• Consider:

– Computer science: efficiency is measured in human-centric terms – Library science: Dewey Decimal system = technology – HCI: the purpose of humans interfacing with computers is information transfer

My Thesis:

• Adapting the abstraction hierarchy model

to complex information systems design can aid in achieving the ability for those systems to adapt to novel or extraordinary

• circumstances. (Critical Incident

Information Management Systems)

• Demonstration application: CIIMS for

Emergency Services Dispatch

Approach:

• An abstraction hierarchy (AH) was

developed which targets the composition

• f a comprehensive information system. In

contrast to the typical abstraction hierarchy’s whole-part decomposition of systems into sub-systems, units, assemblies, and components, I have implemented a decomposition of the system into the three peer elements of information, technology, and people.

General I-T-P AH Model

Structural Decomposition

Information Technology People Purpose / Goal

Overall outcome improvement

Abstract Function

Description of environment and conveyance of decision makers’ wishes Understanding and manipulation of environment

Generalized Function

Refined or transformed data which accurately describe relevant conditions and users’ wishes in a timely fashion Organization, transformation, refinement, storage, movement, presentation, etc.

• f data

Understanding of variables describing actual and desired conditions

Real-World Function

Representation of exhaustive set of available details Presentation of data to users, and interpretation of users’ directions Analysis of conditions and direction of activity

Level of Abstraction

Real-World Form

Raw Data Data communications / storage / processing capabilities, interface hardware / software, database structure, decision support algorithms, etc. Users

Approach:

• Work Domain Analysis
• Populate AH model’s cells
• Infer needs of CIIMS from the model
• Develop initial prototypes
• Enter development cycle

Work Domain Analysis

• Literature Review: EMD, ATC, Emergency

Medicine (for both content and methodology)

• Prior involvement
• Site visits to interview/observe EMD

activity

Beaver Stadium EMS

• ~108K spectators +

surrounding parking areas making it the 3rd largest population center in PA

(http://wpsx.psu.edu/ourtown/statecollege/1.html)

• >40 response teams with

varying capabilities

• 10-20 incidents per game,

with large variation in number and type

Site Visits

• Four centers
• Represent different

environments

• Familiar to author
• Interviews with

administrators and dispatchers + observation

Findings of WDA

• Diversity of approach to mission.
• Technology is homogenous,

implementation varies tremendously.

• Current information systems work well for

normal operations, though human element must learn and adapt the most.

• ESD is a “gateway” to ES jobs; not so

much other ESD jobs (probably due to

• perational differences between centers)

Findings of WDA

• Great deal of “free” information movement

between personnel, as well as loosely- formed information held by personnel

• utside of technology.
• Critical incidents inside the ECC do not

necessarily equate to critical incidents in the field.

• Technology can hide information.

Findings of WDA

• Overall goal is appropriate resource

allocation.

• This is approached on an incident-by-

incident basis.

• Current technology-based systems do not

support real-time aggregation of incident data to reveal overall resources/needs status.

WDA – Interesting Observation

WDA I-T-P AH

Structural Decomposition

Information Technology People Purpose / Goal

Minimize loss-of-life, injury exacerbation, property loss or damage

Abstract Function

Meaningful representation of conditions in the context of established triage and protocol criteria Appropriate allocation of resources

Generalized Function

Timely and accurate description of conditions Organization, transformation, refinement, storage, movement, presentation, etc.

• f data

Work assignments (or withholdings) for resource inventory

Real-World Function

Representation of availability and capability

• f resource inventory as

well as requests for resources Maintenance of database integrity with support for real-time data input/output & directed sharing Decisions based upon available data

Level of Abstraction

Real-World Form

Resource inventory and needs assessment data Data structure & accompanying interfaces; data distribution policies (assumes hardware/network infrastructure is in place) Emergency communications personnel

Implications of the completed I-T-P AH model

• Incidents are only a single component of the

information system requirements.

• Resources (police, fire, medical, etc.) and their

specific capabilities are another component.

• Resource availability is based on current

assignment.

• Other factors, notably geography and policy,

influence resource assignability.

• Since these factors are locally defined, CIIMS

must be customized for each implementation.

Conclusions

• The I-T-P Abstraction Hierarchy model can

reveal relationships important to information systems designers.

• Systems built from this model should be

better able to adapt to atypical and novel circumstances.

Future Efforts

• Extend the domain example pool to

business, medicine, etc.

• Quantify performance comparisons.
• Assess variations of the model for
• usefulness. If the I-T-P elements are truly

peers, their arrangement is arbitrary:

Variations of the model (I-P-T)

Structural Decomposition

Information People Technology Purpose / Goal

Increase in overall value of fund

Abstract Function

Description of business environment and conveyance of decision makers’ wishes Understanding and manipulation of environment (buying / selling)

Generalized Function

Refined or transformed data which accurately describe relevant conditions and users’ wishes in a timely fashion Understanding of business practices, legal issues, corporate interactions, etc. Organization, transformation, refinement, storage, movement, presentation, etc. of data

Real-World Function

Representation of exhaustive set of available details Analysis of business conditions and direction to buy/sell particular stocks Presentation of data to users, and interpretation of users’ directions

Level of Abstraction

Real-World Form

Stock market data, business news, trend analysis data, etc. Stock Market Fund Managers Communications links with data warehouses and stock traders, DSS processes and displays, etc.

Variations of the model (T-I-P)

Structural Decomposition

Technology Information People Purpose / Goal

Aid in the design and construction of complex information systems with an emphasis on scalability for complexity increases.

Abstract Function

Documented understanding of scope of system Formulation of possible solutions

Generalized Function

Description of interactions between elemental units Presentation of model Understanding of system requirements and constraints

Real-World Function

Decomposition of system into peer elements Communication of author’s proposal with supporting documentation System models

Level of Abstraction

Real-World Form

The I-T-P Abstraction Hierarchy model My Thesis Information systems designers

Questions?

http://www.personal.psu.edu/acj100/thesis/defense.pdf http://www.personal.psu.edu/acj100/thesis/final.pdf

References

• Flanagan, J. C.; The critical incident technique; Psychological

Bulletin; Vol. 51, No. 4, pp. 327-359; (July 1954).

• Vicente, Kim J.; The Human Factor; Routledge; New York, NY ;

(2004)

• Rasmussen, Jens; Elsevier Science Publishing Co., Inc.; New York,

NY.; Information Processing and Human-Machine Interaction; North- Holland series in system science and engineering; volume 12; (1986)

• Sawyer, S. & Chen, T.; Conceptualizing Information Technology and

Studying Information Systems: Trends and Issues; in Myers, M. & Wynn, E. & DeGross, J. (Eds.) Global and Organizational Discourse About Information Technology,London: Kluwer, pp.109-131; (2002)

• Xia, Weidong & Lee, Gwanhoo; Grasping the Complexity of IS

Development Projects; Communications of the ACM; Volume 47, Number 5; (May 2004)