GIS System Integration
At this point in the GIS development process the GIS hardware and software have been acquired and data conversion is complete (or a substantial portion has been finished). Different components of the hardware and software may have been purchased separately. It is now necessary to put all the pieces together, test them to make sure they work as expected, and to initiate all procedures necessary to use the GIS.
Vendors will usually install and test their software. Acceptance criteria (often the performance measures used during the pilot study or benchmark test) will be needed and the vendors must meet these criteria before you relieve them of their obligation to you. Check the functionality of the program(s) to ensure that you received what you expected. The vendor should fix any problems that arise, either in software functionality or performance prior to you indicating acceptance of the software.
Check that not only the main GIS software works, but that it works in relation to the other software programs that are part of your "total system," which also includes all legacy databases, software, and hardware. In addition to acceptable performance for each individual piece of software, make sure all software works together. Once the total system is your responsibility and problems arise it can be very difficult to determine the part of the system causing the trouble. Although not nearly as common as in the past, the first response of a vendor can still be "blame the other guy!" Make the vendors responsible for providing you with one integrated system. Remember - they are the experts. Do not allow anything to be left up to you to check or test. If you are uncomfortable about something or do not understand how something works, talk to the vendor representative and get an explanation. Additionally, technical support is an extremely valuable necessity. All contracts should include on-site technical support and then on-going phone support after the installation is complete.
Implementing your hardware system is about the same as your software and must occur simultaneously. Contract with the vendor to install and test the hardware components. As with the software, choose acceptance criteria for the hardware and operating system. Check functionality and performance of the hardware and have the vendor resolve any problems. Make sure the hardware is able to support the software, database, and network as required. Technical support, both on-site and telephone, should have been included in the contract with the hardware vendor.
Integrating and testing hardware and software components are fairly well-defined processes and vendors have good experience with these tasks. However, dealing with larger and more complex databases has not been nearly as common in the GIS area. Therefore, adequate procedures and vendor experience may be lacking. There are two processes which remain basically user responsibility:
- building a master database or library (database integration)
- integrating the database with the GIS hardware and software
The overall process of building the master database from the converted data files (the product of the digitizing or scanning process)deals with quality control checking, other editing procedures, correction procedures, checking corrections for accuracy and finally placing the data file into the master database (or library). It is assumed that organizing data entities into logical groups (i.e., layers) has been defined during the previously completed logical/physical database design activity. Processing to enter data into the master database may involve restructuring the content of the digital/scanned files from data conversion into the final database structure, usually combining entities that may have been digitized separately.
Other database building processes that must be accomplished within the activities are:
- linking GIS layers to attribute tables
- edgematching between areas used in digitizing and repartitioning the spatial extent into the final organization
- initialization of all database related procedures needed for both establishing the database and its continued maintenance
Procedural components needed to complete the database include those on the following list. Many of these procedures will have been defined, at least initially, during database design and/or the pilot study and benchmark activities. The procedures are:
- naming convention for all files (covering versions, status, etc.)
- definition of error conditions
- definition of accuracy requirements
- quality control routines
- manual editing procedures
- checking procedures (verification of corrections)
- error recording (flags associated with data or other error/accuracy information recorded in the database
The second major process is the integration of the database and all other system components.
Once the installations are complete, you need to test your integrated system. Test how the software programs work together, how the network is running, are the computers running slowly when complex functions are requested or all workstations are running simultaneously, and if data retrieval is quick enough, to name a few. This process should continue at least a week, if not more. It is important to experiment with the system on multiple days, with different processes running, and with different numbers of people accessing the data. Ask your staff to document any problems and report these to the vendor. See that resolutions are provided back to you in a timely manner. Utilize technical support lines and keep in mind that the vendors are responsible for following through on what they told you would work.
Most hardware and software vendors offer classes to teach new users about their products. You can usually include vendor instruction as part of your contract with them. User groups often offer information sessions on software products where you can learn valuable information. Proper instruction is important, however, and is a step that should not be disregarded.