ILF Identification Rules-Methods Of Software Engineering-Lecture Notes, Study notes of Software Engineering

Download ILF Identification Rules-Methods Of Software Engineering-Lecture Notes and more Study notes Software Engineering in PDF only on Docsity! The following list outlines how the rules are presented: ord element types (RETs) ILF Identification Rules To identify ILFs, look for groups of data or control information that satisfy the definition of an ILF. All of the following counting rules must apply for the information to be counted as an ILF.  The group of data or control information is logical and user identifiable.  The group of data is maintained through an elementary process within the application boundary being counted. EIF Identification Rules To identify EIFs, look for groups of data or control information that satisfy the definition of an EIF. All of the following counting rules must apply for the information to be counted as an EIF.  The group of data or control information is logical and user identifiable.  The group of data is referenced by, and external to, the application being counted.  The group of data is not maintained by the application being counted.  The group of data is maintained in an ILF of another application. Complexity and Contribution Definitions and Rules The number of ILFs, EIFs, and their relative functional complexity determine the contribution of the data functions to the unadjusted function point count. Assign each identified ILF and EIF a functional complexity based on the number of data element types (DETs) and record element types (RETs) associated with the ILF or EIF. This section defines DETs and RETs and includes the counting rules for each. DET Definition A data element type is a unique user recognizable, non-repeated field. DET Rules The following rules apply when counting DETs: 1. Count a DET for each unique user recognizable, non-repeated field maintained in or retrieved from the ILF or EIF through the execution of an elementary process. For example:  An account number that is stored in multiple fields is counted as one DET. docsity.com  A before or after image for a group of 10 fields maintained for audit purposes would count as one DET for the before image (all 10 fields) and as one DET for the after image (all 10 fields) for a total of 2 DETs.  The result(s) of a calculation from an elementary process, such as calculated sales tax value for a customer order maintained on an ILF is counted as one DET on the customer order ILF.  Accessing the price of an item which is saved to a billing file or fields such as a time stamp if required by the user(s) are counted as DETs.  If an employee number which appears twice in an ILF or EIF as (1) the key of the employee record and (2) a foreign key in the dependent record, count the DET only once.  Within an ILF or EIF, count one DET for the 12 Monthly Budget Amount fields. Count one additional field to identify the applicable month. For Example: 2. When two applications maintain and/or reference the same ILF/EIF, but each maintains/references separate DETs, count only the DETs being used by each application to size the ILF/EIF. For Example:  Application A may specifically identify and use an address as street address, city, state and zip code. Application B may see the address as one block of data without regard to individual components. Application A would count four DETs; Application B would count one DET.  Application X maintains and/or references an ILF that contains a SSN, Name, Street Name, Mail Stop, City, State, and Zip. Application Z maintains and/or references the Name, City, and State. Application X would count seven DETs; Application Z would count three DETs. 3. Count a DET for each piece of data required by the user to establish a relationship with another ILF or EIF.  In an HR application, an employee's information is maintained on an ILF. The employee‘s job name is included as part of the employee's information. This DET is counted because it is required to relate an employee to a job that exists in the organization. This type of data element is referred to as a foreign key.  In an object oriented (OO) application, the user requires an association between object classes, which have been identified as separate ILFs. Location name is a DET in the Location EIF. The location name is required when processing employee information; consequently, it is also counted as a DET within the Employee ILF. docsity.com • Attributive Entity Type – An entity type which further describes one or more characteristics of another entity. – Product – Part – Product – Product Price Information • Entity Subtype – A subdivision of entity. A subtype inherits all the attributes of its parent entity type, and may have additional, unique attributes. – Employee Permanent Employee Contract Employee – Employee Married Employee Single Employee Logical Files Grouping of data into logical files is the result of combined effect of two grouping methods: • How data is accessed as a group by elementary processes? (process driven) • The relationship between the entities and their interdependency based on business rules. (data driven) The following guideline can be used for this purpose: • Process Driven Approach • Data Driven Approach Process Driven Approach If several entities are always created together and deleted together then this is a strong indication that they should be grouped into a single logical file. • A customer PO is a single group of data from a user business perspective. • It consists of a header and items information. • From a business perspective, an order cannot be created unless it has at least one item and if the order is deleted both the order header and items are deleted. However the header and the items may have independent maintenance transactions. Data Driven Approach Entity Independence: an entity has significance to the business in and of itself without the presence of other entities. This is a logical file. Entity Dependence: an entity is not meaningful, has no significance to the business in and of itself without the presence of other entities. This is an RET. • Given two linked entities A and B, whether B is dependent or independent: – Is B significant to the business apart from the occurrence of A linked to it? – If we delete an occurrence "a" of A, what happens to occurrence "b" of B linked to "a"? For example in the following scenarios, the first one is the example of entity dependence while the second one is the example of entity independence. docsity.com – Employee – Child – Employee - Company Adopted Child These concepts are summarized in the following table: Definitions: EIs, EOs and EQs This section includes the definitions of EIs, EOs and EQs. Embedded terms within the definitions are defined, and examples are included throughout this definition section. External Inputs An external input (EI) is an elementary process that processes data or control information that comes from outside the application boundary. The primary intent of an EI is to maintain one or more ILFs and/or to alter the behavior of the system. External Outputs An external output (EO) is an elementary process that sends data or control information outside the application boundary. The primary intent of an external output is to present information to a user through processing logic other than, or in addition to, the retrieval of data or control information . The processing logic must contain at least one mathematical formula or calculation, or create derived data. An external output may also maintain one or more ILFs and/or alter the behavior of the system. External Inquiry An external inquiry (EQ) is an elementary process that sends data or control information outside the application boundary. The primary intent of an external inquiry is to present information to a user through the retrieval of data or control information from an ILF or EIF. The processing logic contains no mathematical formulas or calculations, and creates no derived data. No ILF is maintained during the processing, nor is the behavior of the system altered. Summary of the Functions Performed by EIs, EOs, and EQs The main difference between the transactional function types is their primary intent. The table below summarizes functions that may be performed by each transactional function type, and specifies the primary intent of each. Note the primary intent for an EI—this is E/R Concept E/R Term FPA Term IFPUG CPM 4.1 Definition Principal data objects about which information is collected Entity or Entity Type ILF or EIF File refers to a logically related group of data and not the physical implementation of those groups of data. An entity type which contains attributes which further describe relationships between other entities Associative entity type Optional or mandatory subgroup User recognizable subgroup of data elements within an ILF or EIF An entity type that further describes one or more characteristics of another entity type Attributive entity type Optional or mandatory subgroup User recognizable subgroup of data elements within an ILF or EIF A division of an entity type, which inherits all the attributes and relationships of its parent entity type; may have additional, unique attributes and relationships Entity subtype Optional or mandatory subgroup User recognizable subgroup of data elements within an ILF or EIF docsity.com the main difference from EOs and EQs. Some of the differences between EOs and EQs are that an EO may perform the functions of altering the behavior of the system or maintaining one or more ILFs when performing the primary intent of presenting information to the user. Other differences are identified in the section below that summarizes forms of processing logic used by each transactional function. Function Transactional Function Type EI EO EQ Alter the behavior of the system PI F N/A Maintain one or more ILFs PI F N/A Present information to a user F PI PI Legend: PI The primary intent of the transactional function type F A function of the transactional function type, but is not the primary intent and is sometimes present N/A The function is not allowed by the transactional function type. Processing Logic Processing logic is defined as requirements specifically requested by the user to complete an elementary process. Those requirements may include the following actions: 1. Validations are performed. For example, when adding a new employee to an organization, the employee process has processing logic that validates the information being added. 2. Mathematical formulas and calculations are performed. For example, when reporting on all employees within an organization the process includes calculating the total number of salaried employees, hourly employees and all employees. 3. Equivalent values are converted For example, an elementary process references currency conversion rates from US dollars to other currencies. The conversion is accomplished by retrieving values from tables, so calculations need not be performed. 4. Data is filtered and selected by using specified criteria to compare multiple sets of data. For example, to generate a list of employees by assignment, an elementary process compares the job number of a job assignment to select and lists the appropriate employees with that assignment. 5. Conditions are analyzed to determine which are applicable. For example, processing logic exercised by the elementary process when an employee is added and will depend on whether an employee is paid based on salary or hours worked. 6. One or more ILFs are updated. For example, when adding an employee, the elementary process updates the employee ILF to maintain the employee data. 7. One or more ILFs or EIFs are referenced. For example, when adding an employee, the currency EIF is referenced to use the correct US dollar conversion rate to determine an employee‘s hourly rate. 8. Data or control information is retrieved. a) For example, to view a list of possible pay grades, pay grade information is retrieved. 9. Derived data is created by transforming existing data to create additional data. docsity.com