spatial systems development chapter 6 slides from james pick, geo-business: gis in the digital...

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.Copyright (c) 2008 by John Wiley

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.


GIS Development Phases

(Fig. 6.1)Copyright (c) 2008 by John Wiley and Sons

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?


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.


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.


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.


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.


Table 6.1 Tomlinson’s Ten-Stage GIS Planning Process, Compared to Systems Development Phases

TOMLINSON PLANNING STAGES

SYSTEMS DEVELOPMENT PHASES

1. Consider the strategic purpose

2. Plan for the planning

1. Planning

3. Conduct a technology seminar

4. Describe the information products

5. Define the system scope

2. Analysis

6. Create a data design

7. Choose a logical data model

8. Determine system requirements

9. Consider benefit-cost, migration, and risk analysis

3. Design

10. Make an implementation plan 4. Implementation

5. Maintenance

Source: Tomlinson, 2003


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.


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.


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.


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)


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.


(Fig. 6.2)

Example of Data Flow Diagram (DFD) for GIS


Entity Relationship Diagram

(Fig. 6.3)


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)


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.


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.


Flow Diagram in ModelBuilder, a feature of ArcGIS

(Fig 6.4, Source: ESRI, 2007)


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 design-team 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.


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.


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.


Engineering Systems Case – Map of Land Parcel Update and Maintenance, Fairfax County, VA

(Source: Engineering Systems, 2007)Copyright (c) 2008 by John Wiley 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.


spatial systems development chapter 6 slides from james pick, geo-business: gis in the digital...

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