Software Vs Programs

-

  Software = Program + Associated documentation, libraries, support web sites and configuration data needed to make program useful.

Comments

Post a Comment

Popular posts from this blog

Database Normalization : 1NF, 2NF, 3NF, BCNF, 4NF

-
Image
What is normalization? Breaking down a table into functionally independent tables Follows three-step procedures {first normal form, second NF, third NF} Why normalization? Reduce data redundancy, and thus data anomalies 1NF All the key attributes are defined There are no repeating groups in the table All attributes are dependent on the primary key 2NF It is in 1NF It includes no partial dependencies Partial dependency : attributes are dependent on only a part of a composite PK Fig: Dependency Diagram 3NF It is in 2NF It includes no transitive dependencies Transitive dependency : nonkey (nonprime) attributes are dependent on another nonkey attribute BCNF A Table is in BCNF when it is in 3NF and contains no non-key attribute that determines a key attribute. – Convert to BCNF by exchanging the determinate with the key attribute and then resolving the partial dependency with a new table. 4NF A Table is in 4NF when it is in 3NF table with no multi-valued dependencies :  – Convert to...
Read more

Waterfall Model : Software Engineering

-
   Waterfall Model (Linear Sequential Model)  Phases: Requirements analysis and definition. System and software design. Implementation and unit testing. Operation and maintenance. Short Description used when requirements are well defined and reasonably stable. eg. adaptation of accounting software to accommodate changes to mandated government regulations. safety critical software are usually developed using waterfall model as lots of analysis and documentation is required before implementation begins. subsystems within a large system may be developed using different approaches. Parts of system that are well understood can be specified and developed using waterfall process model. Appropriate for: Embedded Systems Critical Systems. Larger software systems that are part of broader engineering systems developed by several partner companies. Limitations: difficult for customers to state all requirements explicitly at the beginning of most projects. customers must have patience...
Read more