1 gis development: general issues step1 - needs assessment step2 - conceptual design of gis step3 -...

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GIS Development: General Issues Step1 - Needs Assessment Step2 - Conceptual Design of GIS Step3 - Survey of Available Data Step4 - Evaluation of HW and SW

(Source: GIS AsiaPacific, June/July & August/September 1998; and

New York State Archives GIS Development Guides)

Faculty of Computer Science

University of IndonesiaDr. Aniati Murni

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Manager’s OverviewManager’s Overview

• GIS development is a process of technological innovation and requires management attention appropriate to this type of activity.

• It is critically important for all expected participants in a cooperative GIS venture to fully understand the development process.

• If a smaller unit of government is to reap the benefits of a county-level GIS, they must actively participate in the planning and development effort.Rise

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Why Planning Process Is NeededWhy Planning Process Is Needed

• The use of a GIS requires that large spatial databases be created, appropriate hardware and software be purchased, applications be developed, and all components be installed, integrated and tested before users can begin to use the GIS.

• Several problems of a technology innovation: requires training for staff, inaccurate development time estimates, greater uncertainty about costs.

• A local government should view the GIS projects an opportunity to introduce fundamental change into the way its business is conducted. Rise

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Policy on GIS Project ManagementPolicy on GIS Project Management

• Emphasize advantages of GIS to individual users and entire organization.

• Require high level of competency by all participants.

• Ensure high level of management commitment from all management levels in the organization.

• Require participation in team building and team participation within and between departments.

• Minimize time between user needs assessment and availability of useful products.

• Develop positive attitude toward change within organization.

• Ensure level of technology is appropriate for intended uses. Rise

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Policy on Data SharingPolicy on Data Sharing• The corporate database is a single organization-

wide data resource.

• Establishing the corporate database is much more a question of policy, management cooperation and coordination.

• Sharing of data among government agencies is a virtual necessity.

• The set of state laws and regulations applicable to GIS data are not adequate to resolve cost issues and to facilitate regional data sharing cooperatives.

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Several Issues on Data SharingSeveral Issues on Data Sharing

• Who and how will the data be collected?

• How will the data sharing be arranged? … purchased? … licensed? … other agreement?

• Who will own the data?

• How will the new GIS data be integrated to the existing data files?

• Who will be responsible in updating the data?

• Who will provide the budget for data creation and maintenance?

• Who will provide public access to the data?

• Who will be responsible for data archiving and retention? … of the original? … the copies?

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Benefits from the GIS(Efficiency versus Effectiveness)Benefits from the GIS

(Efficiency versus Effectiveness)

• The local government needs the GIS for maintaining public records, responding to public inquiries for information, conducting studies and making recommendations to elected officials (decision makers), and managing public facilities and services (utilities, garbage removal, transportation, etc.).

• Efficiency (savings) using the query function of a GIS can range from 2 person-years for a smaller town, to 5-8 person years for a large town, to 10 or more person-years for a large county.

• Effectiveness is obtained by better planning and better or more effective decision-making.

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Resources for Developing a GISResources for Developing a GIS

• Developing a GIS involves investment in five areas: computer hardware, computer software, geographic data, procedures and trained staff.

• Developing the geographic database (which includes some of the procedure and staff costs) can account for 60% to 80% of the GIS development cost.

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Staffing Requirements for a GISStaffing Requirements for a GIS

• 3 areas where expertise is needed includes management of the GIS project (GIS project manager), GIS database skill (database administrator), and application development for database and users (GIS software analyst).

• In the case that the three experts are hired, a full-time GIS manager is available on staff.

• Alternatives to staff expansion are consultants and data conversion firms.

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Key points of managing GIS developmentKey points of managing GIS development

• Decision to investigate GIS for the organization – identification of participants (departments within agencies and group agencies, most potential agency as a user or as a contributor most data).

• Decision to proceed with detailed planning and design of the database - applications, data required, and source of data.

• Decision to acquire the GIS hardware and software – preparation of the detailed database plan, plan of benchmark test, schedule for data conversion.

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GIS Development CycleGIS Development Cycle

NeedsAssessment

ConceptualDesign

DatabasePlanningand DesignAvailable

Data Survey

Pilot / Benchmark

HW and SW Survey

DatabaseConstruction

Acquisition ofGIS HW andSW

GIS SystemIntegration

Application

Development

GIS Use and

Database

Maintenance

The GIS development cycle is based on the philosophy that one first decides what the GIS should do and then as a second activity decides on how the GIS will accomplish each task.

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GIS Development: Step1 - Needs Assessment (Source: GIS AsiaPacific, June/July & August/September 1998; and




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NeedsAssessment

ConceptualDesign


Data Survey

Pilot / Benchmark

HW and SW Survey




Application

Development

GIS Use and

Database

Maintenance


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Step 1: Needs Assessment (2)Step 1: Needs Assessment (2)

• The need to understand the project / business.

• Identification the list of needed GIS functions and the master list of needed geographic data.

• Involvement of potential users in describing their needs to the GIS analyst, learning what the GIS capability to accomplish their business, understanding the nature of GIS life cycle, time (significant time lags between needs assessment and the GIS can actually be used, some unforeseen problems) and cost (data collection, maintenance and retention) required.

General Objectives:

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• A needs assessment is required if the local government will be adopting a GIS throughout the organization.

• Without a complete needs assessment each department may proceed to adopt their own system and database which may not be compatible with those of another department.

• The largest benefit for a local government adopting a GIS is to realize efficiencies from common database and the sharing of data among departments.

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Step 1: Needs Assessment (3)Step 1: Needs Assessment (3)• Data/map inventory is not a wise approach:

It does not fully reflect the needs of the department.This approach tends to focus only on the internal data of the

organization while the government emphasizes on data sharing.• One-on-One interview would capture the needs of a dept.:

It needs more time for questionaire design (interview design).It needs time for interviewing process.Interviewing and documenting the needs of potential GIS users.Compiling the results of the needs assessment into the master

data list (entity/parcel - attribute/owner - spatial object/polygon) and the list of GIS function.

--> GIS data model and the GIS specifications.

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• Main activities of conducting interview:Conduct “start-up” seminar or workshop;

Interview each potential user;

Prepare documentation (forms) for each application (interview plan);

Review each application description with the user;

Obtain user approval of and sign-off for each application description.

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• Start-up seminar:

Introduce definitions: what is a GIS, how is a GIS needed by local government (typical application).

Follow the interview procedure: what the interviewee should do, what is expected from the interviewee, who should approve the application description, how the information from the application description will be used.

Conduct a group discussion: to have list of potential users, set of their typical applications, and their existing condition or system.

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• The objectives of GIS planning activities:To ensure that the user requirements will be fully met;

To develop documentation, especially data documentation (metadata), needed to use and maintain the GIS;

To be in a position to participate in data sharing programs with other agencies as additional applications are developed;

To create a permanent record of the data and its use to document agency plans and decisions, and to meet data retention and archiving requirements (retention - archiving - back up);

To use as a base for building a larger, multi-function at some later date.

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Step 1: Needs Assessment (7)Step 1: Needs Assessment (7)• Groups of information (output of needs assessment

process) needed to plan the development of a GIS system includes:Applications to be developed: work flow within a department

as the basis of GIS applications.

GIS functions required: query, display, spatial analysis functions such as overlay analysis.

Data needed in the GIS database: how to collect the data, who will collect the data, how the data will be used.

Data maintenance procedures: based on the work flow and process within and between departments, the responsibility for data creation, updating, and maintenance will become apparent.

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• Common use of the GIS by a local government:

Browse and simple display (automated mapping);

Query and display;

Map analysis and spatial modeling.

• The GIS in a local government is used to:

Respond to public inquiries;

Perform routine operations such as application reviews and permit approvals; and

Provide information on the larger policy issues requiring action by the town board.

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• The information needed to plan the development of a GIS system for each departments is published in a report and shared among another departments and will be used by each department to:

Design the GIS database;

Identify GIS software that will meet the government’s needs;

Prepare an implementation plan;

Start estimating the benefits and costs of a GIS.

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Step 1: Needs Assessment (10)Step 1: Needs Assessment (10)• Required standard forms:

GIS applications - task description: preparing map and table, processing query, conducting particular spatial analysis - map display form, table display form, flow chart form, data flow diagram form, and entity-relationship diagram form.

GIS activities - important information for the user: issuing building permits, conducting public health insurance;

GIS data - important spatial data which is not appeared in any GIS application: ground truth map, peta rupa bumi.

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Plateau orTerrace

GIS Application Description Form

(courtesy of New York State Archives)

Application Identification

Description

Functions

Entities Attributes

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GIS Development: Step2 - Conceptual Design of GIS Step3 - Survey of Available Data

(Source: GIS AsiaPacific, June/July & August/September 1998; and




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NeedsAssessment

ConceptualDesign


Data Survey

Pilot / Benchmark

HW and SW Survey




Application

Development

GIS Use and

Database

Maintenance


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Step 2: Conceptual Design of the GIS (1)Step 2: Conceptual Design of the GIS (1)• Database planning and data life cycle is the single

most important activity in GIS development.

• They include data identification in the needs assessment, inclusion of data in the data model, creation of the meta data, collection and entry of the data into the database, updating and maintenance, retention according to the appropriate record retention schedule.

• The product of the conceptual is a data model which defines the GIS database and supports the detailed database planning activity.

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Step 2: Conceptual Design of the GIS (2)Step 2: Conceptual Design of the GIS (2)

Shelf

LowerSlope

Data Objects Identified During Needs Assessment

Preparation of Data Model

Match Needed Data to Available Data and

Sources

Source Documents: Maps, Images, Air Photos, etc.

Survey and Evaluation of

Available Data

Prepared Detailed Database Plan

Create Initial Metadata

Map and Tabular Data Conversion

Life Cycle of a GIS Database: Source Documents

Add Record Retention Schedules to Metadata

GIS Database

Database QA/QC Editing

Continuing GIS

Database Maintenance

Archives Database Backups(courtesy of New York State Archives)

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• A data model is a formal definition of the data required in a GIS, in the form of (i) a structured list or (ii) an entity-relationship diagram.

• A data model is a formal specification for the entities, their attributes and all relationships between the entities for the GIS.

• The purpose of a data model is to make it possible for both user and GIS analyst agree on the data definitions which is represented completely rigorous and unambiguous fashion.

Data Model

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• Feature is a term derived from cartography while object and entity are terms derived from computer science.

• Object is a thing that can be seen or touched, material thing that occupies space.

• Entity is a thing that has definite, individual existence in reality.

• Feature is the shape, form, or appearance of a person or thing.

• Layer, coverage, and theme are terms that are used to describe the organization of entities and attributes in a GIS.

Several terms for data description in GIS database

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DeepOcean

Shelf

UpperSlope

RiseLowerSlope

Plateau orTerrace

Simple Entity - Relationship (E-R) Diagram

Entities represented as rectangles, relationship as diamonds and attributes as ellipses.

Building Located on Parcel

Resides Owned

by

Occupant Joe Jones Owner Apex Co.

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E-R Model

• Entities;• Relationships between entities;• Attributes of entities or relationships.

• Belonging to;• Set and subset relationships;• Parent-child relationships;• Component parts of an object.

1. Parts of E-R Model:

2. Types of normal relationships:

3. Rules for identifying entities, relationships, and attributes:• A common noun corresponds to an entity type;• A transitive verb corresponds to a relationship type;• An adjective corresponds to an attribute type.

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Each entity and its attribute map into one or more relational tables.

Each relationship is a regular relationship executed by the relational database query system or a spatial relationship and if it is not a standard operation then the indicated operation which usually includes a complex coputation need to be written (using Avenue Script/Macro Language).

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Area terbangun Bangunan kantorBangunan rumah sakitBangunan sekolahBangunan pertokoan

Koordinat Letak

Luas

Milik

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Spatial Data Standard and Metadata Requirements: • Metada is “information about data”: (i) describe the characteristics of the data (entity and attributes) using its standard name, and (ii) provide information on its accuracy and its source and its archiving provision.

• Important functions of metadata: provide (i) a basic data descrption of a data set; (ii) information for data transfer / sharing; (iii) information for entries into clearinghouses to catalogue the availability of data.

• Metadata should serve as: (i) a documentation and data management tool; (ii) data definition, source documentation, management and updating, data archiving and retention requirement; (iii) information to support database description for spatial data clearinghouses.

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DeepOcean

Shelf

UpperSlope

RiseLowerSlope

Plateau orTerrace

An example of metadata tables:

1. Organization InformationName of OrganizationDepartmentRoom/Suite#Number & Street NameCityStateZip CodePhone NumberFax NumberContact PersonExtension NumberE-mail AddressInternet AddressComments

2. Reference InformationFilenameFile FormatAvailabilityCostFile Internet AddressMetadata Created ByDate Metada CreatedMetadata Updated ByDate Metadata UpdatedMetadata Standard NameComments

5. Attribute InformationData Object NameData Attribute NameAttribute DescriptionAttribute FilenameCode Set NameCode Set DescriptionMeasurement unitsAccuracy DescriptionComments

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Step 3: Survey of Available DataStep 3: Survey of Available Data

• Inventory and document maps, tabulars, digital data within the local government as well as data available from other sources such as other local governments and private sector organizations.

• Source of data: interpreted remote sensing data (raster-based), other digital data (such as elevation data), maps (vector-based or CAD files), scanned data (pictures/diagrams), survey data, field data, statistical data.

• Formats: hardcopy/eye-readable format to be digitized into vector format, analog image format (aerial photos), fully digital format (scanned image, remote sensing image, digital elevation model).

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GIS Development: Step4 - Evaluation of GIS HW and SW

(Source: GIS AsiaPacific, June/July & August/September 1998; and New York State Archives GIS Development Guides)



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NeedsAssessment

ConceptualDesign


Data Survey

Pilot / Benchmark

HW and SW Survey




Application

Development

GIS Use and

Database

Maintenance


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Step 4: Survey of GIS Hardware and Software (1)Step 4: Survey of GIS Hardware and Software (1)

• Get informed on local widely used systemStatus of the current hardware and software

market;

What other local companies (consulting firms, universities, governments) are using;

Observe the existing hardware and software combinations;

Local data formats and data conversion facility.DeepOcean

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• Get informed on publicationsSource Book: GIS World Inc.;GIS conference publishers;Scholarly Journals: American Cartographic

Association;Trade Magazines: GIS World;Books with vendor information: ESRI Inc.Vendor Booth;User Groups;Current Users.

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• Identify Specific NeedsSelection between vector components or raster

components;

Mainly handling data or data modeling or Web publishing or heavy on data analysis;

Find technical information from the local vendors;

Acquire practical insights from other users.

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• Know the ProductsSoftware categories: modular or core;

A fully integrated GIS core product may not be necessary;

A small module user-friendly GIS core product may easily suit our needs.

Shelf

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• Selection Process (software)Evaluate software independently from hardware, it is evaluated on

functionality and performance;

It should provide GUI (graphical user interface) so that it will be easy for the user to use the software;

It should provide a programming language that allow the user to develop specific application, to modify the software or to be customized;

It should have a standard to import and export data, standard guidelines for developing application (Open GIS Group);

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• Selection Process (software)The performance factors: (i) how the software is engineered; (ii)

how is the speed of the hardware where the software is implemented;

Make sure the hardware capacity support the software requirements;

Check the possible expandability (such as networking capability, sharing data with other applications, track record of the software developer;

Justify the one-time license fee with an on going maintenance fee and upgrade cost (to get the most current versions of the software, usually 15% to 30% of the initial license fee).

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• Selection Process (hardware) Operating System: GIS will need to fit into the OS plan (type of supported

computer network, in-house of contractor-based technical support skill).

Processor: need fast clock speed (MHz); 32-bit or 64-bit processor are the best (can grab 32 bits of information during each cycle).

Disk: GIS needs a large amount of disk space (10 – 20 gigabytes).

Memory: Random Access Memory (RAM), most applications run better as the amount of memory increases.

Communications: need to retain competent consultant who works with networks, LAN (Local Area Network) within unit (can share printers and database servers, e-mail, and disk sharing, WAN (Wide Area Network) provide entryway into larger networks (outside the unit); and Internet for sharing ideas in a GIS forum, data downloading, getting latest information on product/vendor.

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• Ensure Vendor Support is Available

Support and training should be a key factor in the decision;

Some form of supports include good manual, dedicated technical staff;

For outside vendor, there should be a support agreement with key local hardware vendors;

Asking their performance to the existing user.