File Processing
Traditional File Processing Systems
In the beginning of computer-based data processing, there were no databases. Computers that were considerably less powerful than today's personal computer filled large rooms and were used almost exclusively for scientific and engineering calculations. Gradually computers were introduced into the business world. To be useful for the business applications, computers must be capable to store, manipulate, and retrieve large files of data computer file processing systems are developed for this purpose. As business applications be more complex, it became evident that traditional file processing systems had a number of short comings and limitations. As a result, these systems have been replaced by database processing systems in most critical business applications today. Nevertheless we should have at least some familiarity with the file processing system for the fr Following reasons.
Disadvantages of file processing systems
Program data dependence:
File Description are stored within each application program that access a given file. For example, in the invoicing system one program will access both the inventory pricing file and the customer master file. Therefore that program will contain a detailed description for both the files. As a consequence any change to a file structure requires changes to the file descriptions for all programs that access the file.
Duplication of data:
Since applications are often developed independently in file processing systems, unplanned duplicate data files are the rules rather than the exception. For example order filling system will contain an inventory master file, while invoicing system will contain an inventory pricing file these files undoubtedly both contain data describing company's products such as product description, unit price, and quantity on hand. This duplication is wasteful since it requires additional storage space and increased effort to keep all the files up to date.
Limited data sharing
With traditional file processing systems, each application has its own private files and users little opportunity to share data outside their own applications. It is often frustrating to managers to find that a requested report will require a major programming effort to obtain data from several incompatible files in separate systems.
Lengthy development time
With traditional file processing systems, there is little Opportunity to leverage previous development efforts. Each new application requires that the developer essentially start from scratch by designing new file formats and descriptions, and then writing the file access logic for each new program. The lengthy development, times required are often inconsistency with today's fast paced business environment, in which time to market is a key factor.
Excessive program maintenance
The preceding factors all combined to create a heavy program maintenance load in organizations that rely on traditional file processing systems. In fact, as much as 80 percent of the total information systems development budget may be devoted to program maintenance in such organizations. This of course leaves little opportunity for developing new application.
Traditional File Processing Systems
In the beginning of computer-based data processing, there were no databases. Computers that were considerably less powerful than today's personal computer filled large rooms and were used almost exclusively for scientific and engineering calculations. Gradually computers were introduced into the business world. To be useful for the business applications, computers must be capable to store, manipulate, and retrieve large files of data computer file processing systems are developed for this purpose. As business applications be more complex, it became evident that traditional file processing systems had a number of short comings and limitations. As a result, these systems have been replaced by database processing systems in most critical business applications today. Nevertheless we should have at least some familiarity with the file processing system for the fr Following reasons.
- File processing systems are still widely used today, especially for backing up database systems.
- Understanding the problems and limitations inherent in file processing systems can help us to avoid these same problems when designing database.
Disadvantages of file processing systems
Program data dependence:
File Description are stored within each application program that access a given file. For example, in the invoicing system one program will access both the inventory pricing file and the customer master file. Therefore that program will contain a detailed description for both the files. As a consequence any change to a file structure requires changes to the file descriptions for all programs that access the file.
Duplication of data:
Since applications are often developed independently in file processing systems, unplanned duplicate data files are the rules rather than the exception. For example order filling system will contain an inventory master file, while invoicing system will contain an inventory pricing file these files undoubtedly both contain data describing company's products such as product description, unit price, and quantity on hand. This duplication is wasteful since it requires additional storage space and increased effort to keep all the files up to date.
Limited data sharing
With traditional file processing systems, each application has its own private files and users little opportunity to share data outside their own applications. It is often frustrating to managers to find that a requested report will require a major programming effort to obtain data from several incompatible files in separate systems.
Lengthy development time
With traditional file processing systems, there is little Opportunity to leverage previous development efforts. Each new application requires that the developer essentially start from scratch by designing new file formats and descriptions, and then writing the file access logic for each new program. The lengthy development, times required are often inconsistency with today's fast paced business environment, in which time to market is a key factor.
Excessive program maintenance
The preceding factors all combined to create a heavy program maintenance load in organizations that rely on traditional file processing systems. In fact, as much as 80 percent of the total information systems development budget may be devoted to program maintenance in such organizations. This of course leaves little opportunity for developing new application.
No comments:
Post a Comment