1.Data duplication: When files are duplicated and held in a number of locations situations can arise that will cause data to be inconsistent.
- Corrections or modifications made in one location may not be updated in another. For example, customer address files held by the Accounts Department may be updated while those held by Sales are not updated. For the customer this may mean that the account arrives but the goods do not.
- Modifications made to data files may also lead to less obvious discrepancies. For example a suburb name may be spelt differently in two locations e.g. Allambie, Allamby. A report generated calculating sales to customers by suburb may then include the same customers twice. This may not be obvious if the report is a summary style report.
2. Poor data control: File systems have no centralized control of the data descriptions. Tables and field names may be used in different locations to mean different things. For example, the Sales department’s files may list a customer as having a single Name field that is made up of customers Initial and last name e.g. I Smith. The Accounts department may keep the customer’s name in three separate fields; First name, Initial, Last Name. This may make it difficult to compare the data in the two files or at least require additional time in programming the comparison.
3. Inadequate data manipulation capabilities: Data in traditional file systems is not easily related, particularly if the files have been developed for separate purposes. If the organization requires information to be generated that accesses data from several unrelated files the task may prove difficult or require re-entry of data. For example, in a library the catalogue of books may be held in one file. Books on order for the library may be held in another file. When books are received the catalogue will need to be manually updated if the two files are not related.
4. Program data dependence: File data is stored within each of the applications that use that data e.g., A sales transaction program may have several files relevant to it, Customer, Stock_in_hand, Sale_Info. These files are integrated into the program.
5. Limited data sharing: This dependence of the data on the program means that the files are not necessarily suitable for a new program that is being developed. The new program may need its data in another form or require additional data that is not held.
6. Lengthy development times: Each new application requires development of the program along with the development of the relevant files for that application. Although the data may be held elsewhere in the organization the data will need to be imported or re-entered into the new files. This takes time. As organizations grow and change they need to change their internal applications quickly to meet new demands. Lengthy development times are a disadvantage.
7. Program maintenance: File maintenance can be time consuming in traditional file processing systems. Changes to files mean changes to application programs.