- Geographic Information Systems: Definitions and Features
- Enterprise-wide GIS: The Corporate Database
- Policy Issues in GIS Development
- Management Issues in GIS Development
- Geographic Information Systems: The Development Cycle
- Tasks for GIS Development and Use
This guide is the first of a set of technical support documents to assist local governments in developing a GIS. The set of guides describes procedures and methods for planning the GIS, evaluating potential data sources, testing available hardware and software and planning for its acquisition, building the GIS data base, developing GIS applications, and planning for the long term maintenance of the GIS system and data base. These guides are intended to provide advice on how best to accomplish the GIS development tasks for all levels of local government - from large,urbanized counties to small rural towns to special-purpose districts.
Realistically, large comprehensive GISs will be developed by the larger units of government (counties and cities) individually or, most likely as the leader in a cooperative multi-participant effort. These would involve the individual operating units within that government and/or the smaller units of local government within the common land area of the larger leading unit. Typically, we would expect to see county government taking the lead, but also covering the interest of all other governmental units within the county. Occasionally, there will be situations where smaller units of government (town, special purpose district, or limited purpose GIS application) may have to "go-it-alone" in developing the GIS. These guidelines have been written to mainly address the first case - a county leading a consortium or cooperative effort. Thus, we would expect the GIS development team of a county to be the primary user of these guidelines, in the sense of actually performing the tasks outlined in each document. However, this does not mean the other participants in a GIS should stop reading these guidelines at this point. 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.
The procedures are applicable for use in first-time creation of a GIS, for restructuring an on-going GIS development project, and for the review and further development of an existing GIS. The subject matter of the guides identifies the necessary tasks in a GIS development program, describes appropriate methods to accomplish each task and, where applicable, provides examples and illustrations of documents or other products that result from each task.
The guidelines are designed for use by general-purpose local governments (city, county, town, or village), special purpose governments (utilities, school districts, etc.), and by those who provide assistance to local governments (consultants, academic units, etc.). The guides address the technical steps required to create a GIS, the management tasks required to ensure successful development of the GIS, and the policy issues that should be considered for the effective use of the GIS.
The Role Of Management
Although GIS is often viewed as an arena for the technically sophisticated computer professional, the development of a successful government-based multi-participant GIS is very dependent on proper management participation and supervision. Normal, common-sense management practices are as necessary in a GIS project as in any other major undertaking. In fact, our experience has shown that the recommended management actions may be the most critical aspect of the GIS development process. GIS development is a process of technological innovation and requires management attention appropriate to this type of activity - active as opposed to passive management involvement in the project. Historically, much of the disillusions and disappointment with GIS projects stems not from a failure of the technical components of the GIS but rather from a lack of understanding of the process of technology innovation and the lack of realistic expectations of all parties associated with the project (GIS technicians, potential users, managers, and elected/appointed officials).
Applying the GIS Development Guides by Local Governments in New York State
The overall procedure contained in the GIS Development Guides is very comprehensive and can require considerable time, effort and dollars to complete. This raises the questions:
- Does all of this have to be done?
- What level of detail is appropriate?
- How can smaller governments,villages and towns, special purpose districts, or a single department in a larger jurisdiction, get through this process?
Does everything have to be done? . . level of detail?
Basically, yes. However, the steps in the GIS development process are frequently done in an iterative manner over an extended time period. Also, the steps are not completely independent of one another and so some back-and-forth does happen. It is often useful to make a "first-cut" run through the entire process, writing down what is already known and identifying the major questions that need to be answered. The person who will be managing the development process may be able to do this "first-cut" description in 1 to 2 days. This can be very helpful in getting a feel for the scope of the whole process and then can be used as a decision tool for continuing. The number of times the process is conducted, the amount of detail, and the resources needed to complete the study can be balanced in this way. If the intended implementation will be limited or small, the planning effort and documents can be sized accordingly. It is important, however, that each step be considered and completed at some level.
How can smaller units of local government, such as villages and small towns complete a GIS Plan?
The best situation for a village, small town, or even a smaller, rural county is to be a partner with a larger unit of government, a county, regional agency or utility company that is conducting and/or leading a GIS planning exercise. Participating in a regional GIS cooperative, or joining an existing one, will provide access to GIS technical expertise and spatial data created by other agencies. Additionally, if one is a partner in a larger group, the activities directed toward the evaluation and selection of the GIS hardware and software may not need to be completed. One would simply use the same GIS system in use by the larger agency or group. Only the activities aimed at defining applications (uses) and identifying the needed data would need to be done by the smaller unit of government. In such a situation, the larger unit of government assumes the leadership role for the area-wide GIS and should have the technical expertise to assist the smaller unit. In situations where a larger effort does not exist, a village or town government may want to look at a GIS installation in a similar village or town elsewhere in the state. Given the similarities in local governments within the state, the adoption of the GIS plan of another unit is not unreasonable. That plan should be carefully reviewed by the intended participants in the GIS to ensure applicability. After modifying and validating the plan, a schedule for GIS hardware, software and data acquisition can be prepared consistent with available resources. If a good plan is prepared, there is no reason data acquisition (the most expensive part of a GIS) cannot be stretched over a long time period. Significant data already is available from state and federal agencies at reasonable costs. These data can form the initial GIS database, with locally generated data added later. A list of state and federal data sources is contained in the Survey of Available Data Guide.
Content Of This Guide
This guide presents an overview of the GIS development process. This process is presented as a sequence of steps conducted in a specific order. Each step is important in itself, but more importantly, information needed to complete subsequent steps is assembled and organized in each previous step. The underlying philosophy of the entire series of documents is to concentrate on the GIS data. As well as being the most expensive part of any GIS, the data must be collected, stored, maintained, and archived under an integrated set of activities in order to ensure continued availability and utility to the initial users as well as future users, including the general public. Defining and documenting data elements from their initial definition in the needs assessment through to proper archiving of the GIS database according to state requirements is the constant theme of these guidelines.
Basic Definition Of A Geographic Information System (GIS)
A geographic information system (GIS) may be defined as "...a computer-based information system which attempts to capture, store, manipulate, analyze and display spatially referenced and associated tabular attribute data, for solving complex research, planning and management problems"(Fischer and Nijkamp, 1992). GISs have taken advantage of rapid developments in microprocessor technology over the past several decades to address the special challenges of storing and analyzing spatial data. Geographers have referred to GISs as simultaneously providing "...the telescope, the microscope, the computer and the Xerox machine" for geographic and regional analysis (Abler, 1987).
Unique Features Of A GIS - Why Planning Process Is Needed
GIS belongs to the class of computer systems that require the building of large databases before they become useful. Unlike many micro-computer applications where a user can begin use after the purchase of the hardware and software, 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. These tasks are large and complex, so large in fact,as to require substantial planning before any data, hardware or software is acquired. The focus of the GIS Development Guides is to describe the GIS planning process and to provide examples of how to accomplish the recommended planning tasks.
History Of Technology Innovations - GIS Is A Technology Innovation
It is useful to note that GIS is, at present, a technological innovation. The adoption of technological innovations (i.e., the development of a GIS for a local government) is not always a straightforward process, such as one might expect with the installation of something that is not new. Several problems are likely to occur such as:
- Staff not fully understanding the technology prior to extensive training
- Development time estimates differing from actual task times
- Greater uncertainty about costs
- A greater likelihood that programmatic changes will be needed during the development phases, etc.
The significant management point here is that these are normal conditions in the adoption of a new technology. Management needs to anticipate that such events will happen, and when they do, take appropriate management actions.
The adoption of computer technology by an organization either GIS or other applications, introduces fundamental change into the organization in its thinking about data. Prior information technology allowed data to be collected and related to activities and projects individually. Organized stores of data were the exception rather than common practice. This led to duplicate data collection and storage (as in different departments) and to the possibility of erroneous data existing in one or more locations. One of the goals of computer systems and database development is to eliminate redundant data collection and storage. The principle is that data should be collected only once and then accessed by all who need it. This not only reduces redundancy; it also allows for more accurate data and a greater understanding of how the same data is used by multiple departments. The necessary condition for successful computer system and database development is for different departments and agencies to cooperate in the development of the system. A database becomes an organization-wide resource and is created and managed according to a set of database principles.
The role of a GIS in a local government setting is more than simply automating a few obvious tasks for the sake of efficiency. A local government (or several cooperating governments) should view the GIS project as an opportunity to introduce fundamental change into the way its business is conducted. As with the adoption of management and executive information systems in the business world, the adoption of GIS effectively reorganizes the data and information the government collects,maintains and uses to conduct its affairs. This can, and arguably should, lead to major changes in the institution, to improve both effectiveness and efficiency of operations.
A key factor in the success of computer system adoption in the business world is the concept of the"enterprise" or "corporate" database. As implied by the name, the corporate database is a single,organization-wide data resource. The advantages of the corporate database are first, that all users have immediate and easy access to up-to-date information and, secondly that the construction of the database is done in the most efficient manner possible. Typically, the corporate database eliminates redundant collection and storage of information and the keeping of extra copies of data and extra reference lists by individual users. Here, we are recommending the use of corporate database concept to integrate GIS data for all units of local government participating in a cooperative GIS program.
An effective corporate database does require cooperation on the part of all users, both for the collection and entry of data in the database and in developing applications in a shared data context. This may result in some individual applications or uses being less efficient, however the overall benefits to the organization can easily outweigh these inefficiencies. Greater emphasis must,however, be placed on maintaining a high quality of data and services to users, mainly to offset the perceived loss of control that accompanies sharing an individual's data to another part of the organization.
The corporate database concept can be used in the governmental situation, for either single units of government or between several governmental entities in the same region. The benefits associated with the corporate database can be achieved if governmental units are willing to cooperate and share a multi-purpose regional GIS database. Such an arrangement has some technical requirements; however, establishing the corporate database is much more a question of policy, management cooperation and coordination.
There are several policy issues that need to be addressed early in the GIS planning process:
GIS Project Management
Adequate management attention has already been mentioned in this document. As GIS is still an evolving new technology, the individuals involved (management, users, GIS staff) may have very different expectations for the project, some based on general perceptions of computing, which mayor may not be correct. This, along with the long time period for developing the GIS, makes it very important for substantial involvement of management in the project. Several factors associated with successful GIS projects are:
- 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 & between departments
- Ensure minimum data quality and access for all users
- Require development team to set realistic expectations
- 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
- Highly visible Pilot Project that is successful
The sharing of data among government agencies is a virtual necessity for a successful, long-term GIS. Not even the most affluent jurisdictions will be able to justify "going-their-own-way" and not taking advantage of what data are available from other sources or not sharing their database with other governmental units. This, then, raises several questions that must be considered during the planning of the GIS:
- What will be the source for each data item?
- How will sharing be arranged? . . purchase? . . license? . . other agreement?
- Who will own the data?
- How will new GIS data be integrated with existing data files (legacy systems)?
- Who will be responsible for updates to the data?
- How will the cost of the data (creation and maintenance) be allocated?
- Who will provide public access to the data?
- Who will be responsible for data archiving and retention? . . of the original? ..of copies?
These questions do not, at this time, have good answers. Currently, the Freedom of Information regulations require that all government data be made available to the public at minimal cost (cost of making a copy of the data). No distinction is made on the basis of the format of the data (eye-readable or digital), the amount of data, or the intended use of data. Thus, the question of sharing the cost of a GIS database cannot be addressed in general. If data can be obtained free from another agency, why enter into an agreement to pay for it? The answer is, of course, that the creating agency will not be able to sustain the GIS database under these circumstances. However, at this time, 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. New legislation will be required. The New York State Temporary GIS Council did submit recommendations on these issues to the Legislature in March 1996. Additionally, the New York State Archives is currently in the process of preparing record management and retention schedules suitable for GIS data, both in individual agencies and for shared databases. The New York State Office of Real Property Services has been designated as the GIS representative on the Governor's Task Force for Information Resource Management. One of the charges that has been given to the Task Force is to design a cohesive policy for the coordination of geographic information systems within New York building on the work of the Temporary GIS Council. Further information should be available in late-1996 that should clarify the issues associated with arranging for data sharing among governments.
Expected Benefits From The GIS
Local government need for, and use of, a GIS falls into several categories: 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.). The GIS tasks that meet these uses are:
- Providing regular maps
- Conducting spatial queries and displaying the results
- Conducting complex spatial analyses
Many of these tasks are already done by local government, although by manual means. The GIS is able to perform these tasks much more efficiently. Some of the analytical tasks cannot be performed without a computer due to their size and complexity. In these cases, the GIS improves local government effectiveness by providing better information to planners and decision-makers.
Benefits from using a GIS fall into the two categories of: efficiency and effectiveness. Existing manual tasks done more efficiently by the GIS result in a substantial savings of staff time. In the local government context, the largest savings come from answering citizen inquiries of many types. Depending on the size of the government, 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. Estimates of potential time savings can be derived by measuring the time to respond to a query manually and by GIS and multiplying the difference by the number of expected queries. This information is usually gathered during the Needs Assessment. Effectiveness benefits are more difficult to estimate. The GIS may be used to accomplish several tasks that were not previously done due to their size and complexity (e.g., flow analysis in water and sewer systems,traffic analysis, etc.). As these are essentially new tasks, a comparison between manual and GIS methods is not possible. While not measurable, the benefits from these applications can be substantial. Generally categorized as better planning, better or more effective decision-making, these applications support more effective investment of government resources in physical infrastructure where relatively small performance improvements can translate into large dollar savings. GIS also provides an effective way to communicate the problem and solution to the general public and other interested parties.
Resources Required To Develop A GIS
Developing a GIS involves investment in five areas: computer hardware, computer software,geographic data, procedures and trained staff. The acquisition of the computer hardware and software are often incorrectly viewed as the most expensive activity in a GIS program. Research, some conducted at the National Center for Geographic Information and Analysis at SUNY-Buffalo, has demonstrated that developing the geographic database (which includes some of the procedure and staff costs) can account for 60% to 80% of the GIS development costs. Continuing costs for operation and maintenance are also dominated by the data costs. Coordination of GIS programs, particularly among several local government agencies, can minimize the cost of database construction and maintenance, and can provide for the greatest use of the database, which gives maximum benefits from the investment.
Staffing Requirements For A GIS
Staffing for a GIS is a critical issue. In general, it is not easily feasible to directly expand the local government staff positions to fill the GIS need. There are three areas where expertise is needed:
- Management of the GIS project (GIS project manager)
- GIS database skills (usually called a database administrator)
- Application development for database and users (a GIS software analyst)
Initial creation of the GIS database (digitizing) will require an appropriately sized clerical staff, dependent on the amount of data to be converted. Alternatives to staff expansion are consultants and data conversion firms. GIS database conversion is a front-end staff need that can easily be contracted-out (good quality specifications need to be written for this task). If at all possible, the three functions of GIS manager, GIS software analyst and GIS database administrator should be fulfilled by staff personnel, either by hiring or by retraining existing professionals. When necessary, during the start-up phases of GIS development, the GIS analyst and database administrator functions can be done under consultancy arrangements, PROVIDED THAT A FULL-TIME GIS MANAGER IS AVAILABLE ON STAFF.
The second need is for training of users in general computing, database principles, and GIS use. These topics are covered in training courses offered by most GIS vendors, and after the GIS software has been selected, they are the best source for user training.
Management Decision Points in the GIS Development Program
The "decision" to develop a GIS is made incrementally. The information needed to determine the feasibility and desirability of developing a GIS is not available until several of the planning steps have been completed. The key decision points are:
- Decision to investigate GIS for the organization - the initial decision to begin the process. This is an initial feasibility decision and is based on the likelihood that a GIS will be useful and effective. It is fairly important to identify the major participants at this point - both departments within agencies and the group of agencies, particularly key agencies, the agencies who represent a majority of the uses and who will contribute most of the data.
- Decision to proceed with detailed planning and design of the database - at this time, the applications, data required, and sources of the data have been identified. Applications can be prioritized and scheduled and the benefits stream determined. Also, applications to be tested during the pilot study and the specific questions to be answered by the pilot study will have been determined. A preliminary decision will need to be made as to which GIS software will be used to conduct the pilot study.
- Decision to acquire the GIS hardware and software - this decision follows the preparation of the detailed database plan, the pilot study and, if conducted, the benchmark test. This is the first point in the development process where the costs of the GIS can reasonably be estimated, the schedule for data conversion developed, and targets for users to begin use determined.
Developing a GIS is more than simply buying the appropriate GIS hardware and software. The single most demanding part of the GIS development process is building the database. This task takes the longest time, costs the most money, and requires the most effort in terms of planning and management. Therefore the GIS development cycle presented here emphasizes database planning. Most local governments will acquire the GIS hardware and software from a GIS vendor. Choosing the right GIS for a particular local government involves matching the GIS needs to the functionality of the commercial GIS. For many agencies, especially smaller local governments, choosing a GIS will require help from larger, more experienced agencies, knowledgeable university persons and from qualified consultants. By completing selected tasks outlined in these guidelines local governments can prepare themselves to effectively interact and use expertise from these other groups.
The GIS development cycle starts with the needs assessment where the GIS functions and the geographic data needed are identified. This information is obtained through interviewing potential GIS users. Subsequently, surveys of available hardware, software and data are conducted and, based in the information obtained, detailed GIS development plans are formulated.
It is important to involve potential users in all stages of GIS development. They benefit from this involvement in several ways:
- Describing their needs to the GIS analysts
- Learning what the GIS will be capable of accomplishing for them
- Understanding the nature of the GIS development cycle - the time involved and the costs.
Potential users need to understand that there may be significant time lags between the first steps of Needs Assessment and the time when the GIS can actually be used. Mostly, this is due to the size of the database building task, which can take up to several years in a large jurisdiction.
In addition to understanding that database development takes substantial time, users and managers need to appreciate that GIS is a new technology and its adoption often involves some uncertainty that can cause time delays, on-going restructuring the development program, and the need to resolve unforeseen problems. This set of guideline documents describes the GIS development process in away that will minimize problems, time delays, cost overruns, etc.; however, the occurrence of these situations cannot be completely avoided. The GIS project team and management simply have to be aware that some unforeseen events will happen. GIS development must be viewed as a process rather than a distinct project.
Estimating and planning for the cost of the GIS is a somewhat difficult task. First, it is necessary to recognize that the GIS database will likely be the single most costly item - if a local government develops all of the data itself from maps, etc., this cost can be as much as 70 - 80 % of the total system cost. Thus, acquiring digital data from other GIS systems, government sources or the private sector can be very cost effective. Participating in, or organizing a regional data sharing cooperative or district, can also lead to reduced data costs. When planning for the GIS database, long term data maintenance and retention costs must be estimated as well as the initial start-up costs. Cooperation between agencies with similar data needs may provide the most effective way to achieve long-term data maintenance, retention, and archiving.
The GIS development cycle is a set of eleven steps starting with the needs assessment and ending with on-going use and maintenance of the GIS system. These steps are presented here as a logical progression with each step being completed prior to the initiation of the next step. While this view is logical, it is not the way the world always works. Some of the activities in the process may happen concurrently, may be approached in a iterative manner, or may need to be restructured depending on the size and character of the local government conducting the study and the resources available to plan for the GIS. 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. Under this philosophy, the needs are described first, available resources are inventoried second (data, hardware, software, staff, financial resources, etc.), preliminary designs are created and tested as a third major set of activities, and lastly the GIS hardware and software are acquired and the database is built.
The GIS development cycle is described in terms of 11 major activities. Prior to initiating these studies, the responsible staff in local governments should attend introductory GIS seminars and workshops, GIS conferences, and meetings of specific GIS users' groups, to obtain a broad overview of what GIS is and how others are using these systems.
The 11 steps of the GIS development cycle are:
- Needs Assessment
- Conceptual Design of the GIS
- Survey of Available Data
- Survey of GIS Hardware and Software
- Detailed Database Planning and Design
- Database Construction
- Pilot Study/Benchmark Test
- Acquisition of GIS Hardware and Software
- GIS System Integration
- GIS Application Development
- GIS Use and Maintenance
These tasks are one way of dividing up the entire set of activities that must be accomplished to build a successful GIS. While there are other ways of expressing and organizing these activities, this particular structure has been chosen because it emphasizes data development - data definition, data modeling, data documentation, data capture and storage, and data maintenance and retention. The important point to be made here is not the order or structure of the tasks, but rather that, one way or another, all of these tasks must be completed to have a successful GIS.
In some situations, different methods may be more appropriate than those presented in these guides,or a different level of detail may fit the particular situation of a unit of local government. No matter how simple or complex a given GIS environment is, all of the above tasks should be completed at an appropriate level of detail. In the specific guides of this set, examples of different levels of detail will be provided.
The starting point is the needs assessment. It is assumed that the local government has decided that a GIS may be justified and it is reasonable to expend the resources to further study the problem. A final assessment of the costs and benefits will not be made until several tasks have been completed and the nature and size of the resulting GIS can be estimated. In the process presented here, this final feasibility assessment is made as part of the detailed database planning and design activity.
Each of the major portions of the development cycle identified and briefly described below is further described in a subsequent guideline document.
The GIS needs assessment is designed to produce two critical pieces of information:
- The list of GIS functions that will be needed
- A master list of geographic data.
These two information sets are extracted from a set of GIS application descriptions, a list of important data,and a description of management processes. Standard forms are used to document the results of user interviews. The information gained in the needs assessment activity goes directly into the Conceptual GIS Design activity.
Conceptual Design of the GIS System
The conceptual design of the GIS system is primarily an exercise in database design. It includes formal modeling (preparation of a data model) of the intended GIS database and the initial stages of the database planning activity. Database planning is the single most important activity in GIS development. It begins with the identification of the needed data and goes on to cover several other activities collectively termed the data life cycle - identification of data in the needs assessment,inclusion of the data in the data model, creation of the meta data, collection and entry of the data into the database, updating and maintenance, and, finally, retention according to the appropriate record retention schedule. A complete data plan facilitates all phases of data collection,maintenance and retention and as everything is considered in advance, data issues do not become major problems that must be addressed after the fact with considerable difficulty and aggravation. The product of the conceptual design activity is a data model which rigorously defines the GIS database and supports the detailed database planning activity.
The conceptual design of the GIS also includes identification of the basic GIS architecture (type of hardware and GIS software), estimates of usage (derived from the Needs Assessment), and scoping the size of the GIS system. All of this is done with reference to the existing data processing environments (legacy systems) that must interface with the GIS. This guideline also includes a section on metadata and data standards.
Survey Of Available Data
A survey of available data can commence once needed data have been identified in the Needs Assessment. This task will inventory and document mapped, tabular and digital data within the local government as well as data available from other sources, such as federal, state, or other local governments and private sector organizations. The entries in this inventory may include other GIS systems within the local area from which some of the needed data may be obtained. If there exists an organized data sharing cooperative or other mechanism for government data sharing, it should be investigated at this time. There also exists the possibility that one or more of the commercial GIS database developers may be able to supply some of the needed data and should therefore be investigated. The documentation prepared at this point will be sufficient to evaluate each potential data source for use in the GIS. Information collected at this point will also form part of the meta data for the resulting GIS
Survey Of Available GIS Hardware And Software
Almost all local government GIS programs will rely on commercially available GIS software. As a result, a survey of the available GIS systems needs to be conducted. During this activity, the GIS functionality of each commercial GIS system can be documented for later evaluation.
Detailed Database Design And Planning
The detailed database planning and design task includes the following activities: developing a logical or physical database design based on the data model prepared earlier, evaluating the potential data sources, estimating the quantities of geographic data, estimating the cost of building the GIS database and preparing the data conversion plan. Concurrent with the detailed planning for the database, pilot studies and/or benchmark testing that are desired can be executed. Information gained from these studies and tests will be needed to estimate the size of the equipment (disk space, main memory etc.) and to determine how much application development will be necessary. Subsequently, plans for staffing, staff training, equipment acquisition and installation, and user training must be completed. After the preparation of all these plans, the entire cost of the GIS will be known and the final feasibility assessment can be made.
Pilot Study And Benchmark Tests
Pilot studies and benchmark tests are intended to demonstrate the functionality of the GIS software -simply put, what the commercial GIS from the vendor can do. These tests are useful to demonstrate to potential users and management what the GIS will do for them. Also, performance data of the GIS system can be determined.
GIS Database Construction
Database construction (sometimes referred to as "database conversion") is the process of building the digital database from the source data - maps and tabular files. This process would have been planned during the previous activity and the main emphasis here is management of the activity and quality assurance/quality control of the converted data. The conversion process is often "contracted-out" and involves large quantities of source maps and documents. Close and effective management is the critical factor in successful data conversion.
GIS System Integration
Unlike many other computer applications, a GIS is not a "plug and play" type system. The several components of a GIS must be acquired according to well documented specifications. The database must be created in a careful and organized manner. Once all the individual components have been acquired, they must be integrated and tested. Users must be introduced to the system, trained as necessary, and provided with adequate assistance to begin use of the GIS. Parts of the GIS which may appear to work fine individually may not work properly when put together. The GIS system staff must resolve all the problems before users can access the GIS.
GIS Application Development
"Application" is a general term covering all things that "go on" in a GIS. First, there are "database applications." These are all the functions needed to create, edit, build, and maintain the database,and are usually carried out by the GIS systems staff. Some users may have responsibility for updating selected parts of the GIS database, however the entire database should be under the control of a "database administrator." Other applications are termed "user applications." Contemporary GISs provide many simple applications as part of the initial software package (e.g., map display,query, etc.). More complex applications, or ones unique to a particular user, must be developed using a macro-programming language. Most GISs have a macro-programming language for this purpose (e.g., Arc Macro Language (AML) in ARC/INFO. and Avenue in ArcView). The applications needing development by the GIS systems staff will have been described during the Needs Assessment on the GIS Application forms.
GIS System Use And Maintenance
After having described the rather large task of creating a GIS, we can now say that use and maintenance of the GIS and its database will likely require as much attention as was needed to initially build it. Most GIS databases are very dynamic, changing almost daily, and users will immediately think of additional applications that they would like to have developed. Formal procedures for all the maintenance and updating activities need to be created and followed by the GIS system staff and by all users to ensure continued successful operation of the GIS.
This document has presented an overview of the GIS development process, with an emphasis on data and database issues. All of the tasks and issues identified in this document will be described in detail in the remaining eleven guidelines of this series. The procedures are presented as "guides," and not as a "cookbook recipe" which must be rigorously followed. Each of the major tasks in the GIS development process and the information generated within the task should be addressed in any specific project. The methods and forms used in this series can be used, or alternatives can be developed,as appropriate to the situation. The one matter to always keep in mind is that the GIS plan is a document to communicate user needs to a GIS analyst. The components of the plan must contain:
- Descriptions of applications that are understandable to the user
- A logical translation of user requirements to system specifications
- Detailed specification suitable for system development
Following the recommendations in these guidelines cannot, unfortunately, guarantee success. Many of the factors, outside the control of the GIS development team, will affect the ultimate success of the GIS - success being defined as use of the GIS by satisfied users. However, the authors of these guidelines believe that attempting to develop a GIS without following these, or similar procedures, substantially raises the probability of an unsuccessful GIS project - either one that is not useful or one that substantially exceeds both cost and development time estimates.
Finally, although presented here as an independent activity, GIS development must recognize and interface with other computer systems in local government, such as E911, police and fire dispatch, facilities management systems, etc. . The GIS must not be viewed as independent of the other systems, but integrated with them, no matter how difficult, to form a true corporate database for local government.
- Fischer, Manfred M. and Nijkamp, Peter, "Geographic Information System, Spatial Modeling, and Policy Evaluation," Berlin & New York: Springer-Verlag, 1993, pg. 42.
- Abler, R.F., 1987, "The National Science Foundation National Center for Geographic Information and Analysis" International Journal of Geographical Information Systems, 1, no. 4, 303-326.
- Antenucci, John C., et.al., Geographic Information Systems: A Guide to the Technology, New York: Van Nostrand Reinhold, 1991 (ISBN 0-442-00756-6)
- Aronoff, Stan, Geographic Information Systems: A Management Perspective, Ottawa: WDL Publications, 1989 (ISBN 0-921804-00-8)
- Burrough, P.A., Principles of Geographical Information Systems for Land Resources Assessment, Oxford: Oxford University Press, 19865. (ISBN 0-19-854563-0); ISBN 0-19-854592-4 paperback).
- Huxhold, William E., An Introduction to Urban Geographic Information Systems, Oxford: Oxford University Press, 1991 (ISBN 0-19-506534-4)
- Korte, George B., A Practitioner's Guide: The GIS Book, Sante Fe: OnWord Press, 1992 (ISBM 0-934605-73-4)
- Laurini, Robert and Derek Thompson, Fundamentals of Spatial Information Systems, London: Academic Press Limited (ISBN: 0-12-438380-7)
- Montgomery, Glenn E., and Harold C. Schuck, GIS Data Conversion Handbook, Fort Collins: GIS World, Inc. (ISBN 0-9625063-4-6)
GIS INFORMATION SOURCES
There are a number of scholarly journals that deal with GIS. These are published on an on-going basis.
- Cartographica - Contact: Canadian Cartographic Association
- Cartography and Geographic Information Systems - Contact: American Cartographic Association
- International Journal of Geographical Information Systems - Contact: Keith Clark at CUNY Hunter College, New York City
- URISA Journal - Contact: Urban and Regional Information Systems Association
There are a number of trade magazines that are focused on GIS. They are:
GIS World Inc.
155 E. Boardwalk Drive
Fort Collins, CO 80525
GIS World, Inc.
155 E. Boardwalk Drive
Fort Collins, CO 80525
Geo Info Systems
859 Williamette St.
Eugene, OR., 97401-6806
WWW site: http://www.advanstar.com/geo/gis
859 Williamette St.
Eugene, OR., 97401-6806
WWW site: http://www.advanstar.com/geo/gis
American Congress on Surveying and Mapping (ACSM)
5410 Grosvenor Lane
Bethesda, MD, 20814
American Society for Photogrammetry and Remote Sensing (ASPRS)
5410 Grosvenor Lane
Bethesda, MD, 20814
Association of American Geographers (AAG)
1710 Sixteenth St. N.W.
Washington D.C., 20009-3198
Automated Mapping/Facility Management International (AM/FM International)
14456 East Evans Ave.
Aurora, CO, 80014
Canadian Association of Geographers (CAG)
Burnside Hall, McGill University
Rue Sherbrooke St. W
Montreal, Quebec H3A 2K6
Canadian Institute of Geomatics (CIG)
206-1750 Rue Courtwood Crescent
Ottawa, Ontario, K2C 2B5
Urban And Regional Information Systems Association (URISA)
900 Second St. N.E.
Washington, D.C. 20002