Spatial Systems Development
Chapter 6 Slides from
James Pick, Geo-Business: GIS in the Digital
Organization, John Wiley and Sons, 2008.
Copyright © 2008 John Wiley and Sons.
DO NOT CIRCULATE WITHOUT
PERMISSION OF JAMES PICK
Copyright (c) 2008 by John Wiley
and Sons
Lecture topics covered
• Another side of the entire Geo-Business field
concerns how those applications are designed
and developed
• The central theme is designing and developing
spatial systems, rather than operating them.
• This material draws from the subject matter of
systems analysis and design from Connections
A.
– This includes the system development life cycle
(SDLC) and system development methods.
– Outsourcing and end user development are
alternatives used for GIS.
• The Engineering Systems case will be discussed
as a class breakout.
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and Sons
GIS System Development Steps
• The major steps for GIS are the same as
for IS.
• The steps of Planning, Analysis,
Design, Implementation, and
Maintenance must be followed or risk a
faulty system, wrong system, or too
costly system.
• The steps do not have to be followed in
order. Also, they can be repeated by
looping back, if necessary.
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GIS Development Phases
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and Sons
(Fig. 6.1)
Planning Step
• Conceptualizing the system, doing broad
planning, and justifying the need for a GIS.
• It ends by the decision of top management
on whether or not to commit to the project.
Class Question. Can you give an
example, outside of GIS, of a Planning
step, leading to a decision of top
management?
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Analysis Step
• Analysis emphasizes discovery and information gathering, leading
to identifying a set of alternatives.
• Feasibility and cost-benefit are weighed before prioritizing a list of
alternatives that is presented to top management.
• For instance, a large insurance firm is analyzing what GIS would be
best to implement for underwriting and environmental modeling
applications.
• It needs to gather information on the sources of data, types of
architectures (client-server, web), and types of analytical tools to
solve the problems.
• In the process, it discovers a third GIS use for the firm -- marketing.
It determines four alternatives to be feasible and beneficial, and
presents them in priority order to top management for an executive
decision on whether to go forward with one of them.
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Design Step
• The system and data specifications are
worked out in much more detail.
• It involves diagramming, researching, and
specifying of the fine points of the
prospective system.
• Users are extensively consulted on details
of what is being designed.
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Implementation Step
• The spatial application is actually built, based
on the detailed design.
• The design group has a key decision to make
here of whether to build it in-house, purchase
it commercially, or outsource it.
• In this phase, the in-house and customer
users are trained in how to use the system.
• The actual cutover to the new spatial system
takes place and the system is turned on.
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Maintenance Step
• The system is up and running, but users are
continuing to have issues and problems
including training, correcting bugs, and
requesting features be added that were left off
the original system.
• These problems are addressed, often over many
years.
• The final disposition of the system involves its
abandonment or replacement. In the latter case,
the replacement is the result of a new systems
development process.
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Table 6.1 Tomlinson’s Ten-Stage GIS Planning Process, Compared to
Systems Development Phases
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
TOMLINSON PLANNING STAGES
SYSTEMS DEVELOPMENT PHASES
Consider the strategic purpose
Plan for the planning
Conduct a technology seminar
Describe the information products
Define the system scope
Create a data design
Choose a logical data model
Determine system requirements
Consider benefit-cost, migration, and
risk analysis
Make an implementation plan
1. Planning
2. Analysis
3. Design
4. Implementation
5. Maintenance
Source: Tomlinson, 2003
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Methods, Models, and Tools for
Systems Development
• The user doesn’t have to invent systems
development. There are many fine techniques
available.
• For instance, there is Computer-Assisted
Software Engineering (CASE)
• Rapid Application Development (RAD) and
Prototyping are used to speed up development.
• These methods are covered more thoroughly in
Connections A. They also have detailed
explanation in Chapter 6.
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Example of rapid design from the cases
– Motion-Based Technologies
• Motion-Based Technologies used a combination
of RAD and prototyping to build its web-based
spatial applications for high-performance
athletes.
• As a start-up, the firm’s experienced web
programmers wanted to move quickly.
• They could do so since the small firm had an
informal, flexible atmosphere without systems
project procedures and controls.
• The feedback was limited since the firm was
small, so feedback and improvements have
come mostly from live users.
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Tomlinson’s “Technology Seminar”
• Tomlinson proposed the “Technology Seminar”
• It occurs very early in planning a GIS project.
• It is similar to JAD method, i.e. a group meeting
that leads to intensive analysis.
• For GIS, it’s called by the GIS manager early in
a project.
• The seminar group goes from a dozen for small
organizations to 30+ for large ones.
• Group consists of key GIS-user department
heads, some key staff users, the CIO, some
middle managers, and a few executives.
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Agenda for a “Technology Seminar”
• GIS definition
• GIS terminology
• Functions of a GIS. This might include demonstrating
examples of spatial hardware and software for
exposure and training, not giving bias.
• The planning process: steps and responsibilities
• Initial identification of first requirements for the new or
updated GIS system
• The key question for such a Technology Seminar is what
information is needed for you from the spatial system?
(Source: Tomlinson, 2003)
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Some methods used in Design
• Data Flow diagrams (DFDs) show the flow
of data from its origin to its final storage or
disposal.
• Entity Relationship Diagrams (ERDs)
show how the data are related in a firm.
• A Flow Diagram in ESRI’s ModelBuilder
automates the processing flows for a
project.
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Example of Data Flow Diagram (DFD) for GIS
(Fig. 6.2)
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Entity Relationship Diagram
(Fig. 6.3)
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Criteria to Evaluate Spatial Data in
Systems Development
• Scale.
The map scales need to be not too large, which makes data storage
unacceptably large, and not too small which lowers resolution and
weakens the business purpose. Scale needs to be compared so map
layers have the same scale and remain accurate.
• Resolution.
Resolution is closely tied to scale. It shows the smallest map features
that can be identified for a certain scale. Thus it needs to be fine
enough to satisfy the business problem solving with the given map.
• Map Projection.
The map projection of each map needs to be known and accurate.
There needs to be a check done that the conversions can easily be
done into a common projections for all the layers on a map.
• Error Tolerance.
The error tolerance is an estimate of the maximum error that can be
tolerated for particular business problem. Once the tolerance is
determined, the project team needs to estimate the cost to achieve
that tolerance.
(Source: Tomlinson, 2003)
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Example of how to obtain data for a
spatial system: Kaiser Permanente
• Kaiser Permanente, the California-based
healthcare firm, applies GIS for travel-time
analysis, site selection, regulatory reports, a
library of reference maps for members posted
on intranet, spatial web services for members,
support for an ambulance service in the Bay
Area, epidemiology research studies, sales and
market, and finance/accounting.
• For these applications, government, commercial,
and in-house data serve as input to the GIS.
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Kaiser Permanente (cont.)
• The finance/accounting data and epidemiology data are
proprietary and in-house.
• The travel-time analysis is based on street-map data
from commercial vendor TeleAtlas and the PEMS data
on freeway performance measurement from a state
government-university consortium (PEMS, 2007).
• The data for map services for members comes from a
commercial service.
• The data for the intranet library of reference maps is
mostly in-house and proprietary such as member
locations, but utilizes some government data.
• Kaiser’s GIS is not put in one central repository but
resides in many locations keyed to specific projects
throughout the firm.
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Flow Diagram in ModelBuilder, a
feature of ArcGIS
(Fig 6.4, Source: ESRI, 2007)
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and Sons
Cartographic Design: A Special
Part of Design for Spatial Systems
• Cartographic design focuses on cartography, the art of
giving appealing and readable appearance to maps which
was covered in the Clarke book.
• GIS software packages have built-in cartographic
frameworks, but they are not high-level cartography keyed
to the particular GIS problem at hand.
• Cartographic design can be improved by having a designteam or consulting cartographer add requirements for
cartography. Some software packages allow the
cartography to be replicated for an entire project.
• For example, ESRI’s geodatabase feature allows a
cartographic format to be entered which will enforce
consistency across all maps in the project, even new ones.
In short, the cartography can be specified as part of the
design.
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Systems Development in the
Book’s Research Cases
• The cases in the book give guidance about how
GIS and spatial applications are being
developed and implemented in the real world.
• Based on this limited sample, development has
been mostly formal except for small businesses.
• The approach is mostly traditional rather than
object-oriented.
• Development tends to be spearheaded by the
GIS group.
• Outsourcing to outside firms has a fairly small
presence in the sample, but two of the case
companies are outsourcers.
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Case Study – Engineering Systems
• Engineering Systems (ES) is a small, Los
Angeles-based GIS consulting firm that employs
fifteen people. Its primary customer base
consists of local and county government
agencies in California and Virginia, with
secondary emphasis on private companies.
• Examples of its clients include San Bernardino
County, City of Downey, and Metropolitan Water
District in southern California; and the Town of
Vienna, City of Falls Church, and Fairfax County
in Virginia.
• ES provides GIS planning, development, and
implementation consulting services.
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Engineering Systems Case – Map of Land Parcel
Update and Maintenance, Fairfax County, VA
Copyright (c) 2008 by John Wiley (Source: Engineering Systems, 2007)
and Sons
Summary
• Systems development of GIS and spatial technologies is
a crucial part of business success with them.
• The reason is that an organization cannot just rest on
what GIS system it has now, but needs to continue to
improve, update, and expand.
• This lecture has given background on the approaches to
systems development, the phases of systems
development projects, who does this, why the users are
crucial, and what some of the methods, techniques, and
models are.
• The case of Engineering Systems illustrates many of the
chapter concepts.
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and Sons