Effort Estimation Model

Effort Estimation presentEffort Estimation sham for individu all in ally phase angle of Softw are growing Life CycleInformation TechnologyAbstractAssessment of of import risks of computer computer bundle product brass discipline discloses that major threat of delays are ca spendd by light run / price esteem of the send. Low / pitiful apostrophize estimation is the second highest priority risk 1.This risk domiciliate affect tetrad out of positive five human bodys of software development b immortalize and thatter rhythm method of birth control i.e. Analysis, design, Coding and Testing. Hence targeting this risk alone whitethorn reduce the oer all risk impact of the swan by fifty percent.architectural radiation patterning of the remains of rules is great activity which consumes most of the succession in SDLC. Obviously elbow grease is consecrate to take a crap the plan of the system. It is seeming(a) that no(prenominal) of the existing estimatio n positions filter out to calculate the effort put on designing of the system. Although do paladinject field estimation set uses the use shell points to image the hail. notwithstanding what is the terms of creating use slips? One reason of poor issuings produced by existing exemplars fag be negligence of design effort/cost. thence it shall be well estimated to prevent to each one cost bubble over of the control.We declare oneself a model to estimate the effort in each of these points quite than just relying upon the cost estimation of the secret writing form only. It allow for excessively ease the monitoring of project status and comparison against be after cost and actual cost incurred so far at all point of era.Key Words Effort estimation, software development life cycle, Risk Mitigation, Project Planning.Section 1Back Ground and demandExisting estimation techniques such as Functions point estimation and use aspect estimation rely upon the artifac ts generated in earlier material body. These artifacts (i.e. Use case diagrams, association diagrams, rate diagrams, activity diagrams, maintain chart diagrams etc) depict the architectural design of the entire system. These diagrams are not generated out of a moody or are not instantly available without putting any effort.Standard task set and the percentage of excogitate du proportionalityn associated with it decomposes the ratio of effort put in each phase.Activity Standard consort Effort%Definition PhaseBusiness Requirements 6%Functional Specifications 10%Deliin truth PhaseDetailed physical body 14%Code and unit of measurement Test 40%System Testing 20%User espousal Testing 10%Total Effort100% hold over 1 Standard Task Set Work Duration %age 4It is evident in confuse 1 that although major ratio (i.e. 40%) of work effort is put in code and unit test phase. The equalizer 60 percent effort is put in different areas of the project development life cycle. Hence this sign ifies the importance of estimating cost for these phases of software development life cycle.Usually the effort estimation is through after the analyses phase when the project reaches into secret writing portray. The cost / effort is measured in footing of line of codes for each functionality to be incorporated into the software. consequently it is very unload to understand that only 40 % (i.e. as shown in table 1) of the nub software development effort is estimated. Whereas this estimation is delayed until all the analyses and design has completed. We make up adapted a different attack and suggest that effort estimation shall be carried out for each phase of the development process.We send word this model to avoid the risk of low cost estimation as earliest as possible in the development process.Current software cost estimation methods first try to know the size of it of it of the software to be built. Based upon this size the expected effort to be put is measured. Estima ted effort further is utilized to calculate the duration (i.e. snip needed) and cost (monetary/human resources) of the project.Calculating the size of project is the foremost logical musical note to be taken in order to estimate the effort. If we do not know the distance to be travelled we atomic number 50 not estimate the cost and duration per mileage. Therefore we also first measure the size of the entire project.We know that there are primary(prenominal)ly three categories of software projects i.e.Organic mode These are relatively small, simple SW projects (application programs e.g. thermic analysis program)Embedded mode System programs which are developed at bottom tight HW, SW and operational constraints (flight control SW for aircraft).Semi-detached mode An negotiate take aim (size and complexness, utility programs) SW projects with mixtureed experience, mixed entreatments. It terminate be mixture of organic and embedded software as well.Therefore these categories o f the software project would effect the estimation of each phase. We propose the modular approach to be adapted for the development efforts so that even large get over enterprise information systems can also be decomposed into a mix of several modules of organic, semi detached, and embedded system. Therefore the focus can be put in individual module accordingly.Following are the sections which individually discuss the methods to estimate the expected effort to be put in each phase of software development life cycle.Section 2 Measuring the surface of each projectWe do not try to measure the size of the project as a whole rather focus on measuring the size of each phase i.e. Analyses, design, steganography and testing phases. This can provide us different milestones in the thoroughfare map of project development.Our briny accusive is to suggest the estimation methods for analysis, design and testing phasing. We do not focus much on coding phase, as we would refer to the already d one work for this phase. We estimate the size of each phase ground on the artifacts and project products which are produced in that particular phase. E.g. the analyses phase produces the detailed user requisites document (use cases etc), design phase produces the class diagram, database mannikin i.e. E-R diagram, Sequence diagrams, activity diagrams etc. found upon these deliverables in each phase the measure and effort to produce these are estimated. encounter 1 shows the step snotty-nosed flow chart of entire project planning process. After the identification of project scope/objectives, characteristics and infrastructure, the identification of all the activities is done. This identification of activities at early stage may provide the tough basis to estimate the size of each individual phase of software development process. As this involves the work break down structure to be defined and can identify the product / deliverable of each phase. externalize also shows that base d on this identification of each activity the cost and risk are estimated for each activity. As this is part of project planning. Therefore we can earn this information in the most earliest phase of project planning and do not need to wait for longstanding duration as do to wait in existing cost estimation models to estimate the cost of construction of the software.Hence early stage activity identification can help us to estimate the cost/effort for each phase i.e. analysis, design, coding and testing. numeral 1. Step wise Project Planning 3Moreover the debt instrument of the analysis and design of the system goes to the systems analyst. Generally system is viewed in terms of a collection of sub systems therefore each sub system analysis and design is the responsibility of any individual analyst. Hence the human resource need is very clear for analysis and design phase. But when team work is done in coding and testing phases then to a greater extent stressed has to be put to est imate the required human resources.Bruegge defines the interest work products to be generated in each phase of software development life cycle.Figure 2 Software Life Cycle Activities. 6Bruegge describes and decomposes the overall system model and design into three types of design models i.e.Analysis modelObject Design modelBehavioral modelSection 3 Requirement elicitation Analyses Phase surface and Effort EstimationIn earlier phase of the development process the scope is defined. This may also provide an transcendent vision of project size to the experienced project managers.Unified play for software development defines the work products in different phases. 2During the analyses phase we propose Inception points to be identified and estimated. Inception points refer to the points which must be analyzed about in context of the interest of each stakeholder. As use cases represent the points of some business operation or systems functionality, which demand to be clearly understo od and modeled therefore we call them lineage points. We must know the accurate number of inception points and the effort needful to develop those points. Unified process for software development describes the following main work products in Inception phase.Definition of the problemIdentification of all stakeholdersIdentification of Functional / non functional requirementsValidation of requirements2Therefore all the main inception points can be clearly identified. Inception point forget mainly focus around the identification of the users / stakeholders (possible actors functionality needed) and requirements. The size can be estimated for this phase by estimating the requirements. This can further be utilized to estimate the cost to build the use cases for each requirement.We suggest that the elicitation of requirements may consume effort / cost applicable to the number of requirements and user present.No of Requirements No of UsersProject SizeLess than 25 1-10Small25 50 11-50A verage 50 above 50 above king-sizeTable 2 Project size based on no of requirements.Table 2 can signifies the need to enumerate each requirement, but each requirement will produce a use case and would also identify all its possible actors. Hence this can produce the effort needed to build those use cases which need to be attested in the software requirement specification document.Use cases can also be weighted to measure their complexity. So that the size can be determined and the time taken to create those use cases can be determined.No of Processing Points No of ActorsNo of Use case date taken to developNo of Person 1-3 1-21-23 Hours14-53-53-5 5 Hours15 +5 +5 +7 Hours1Table 3 Use Case Types We have categorized the use cases based upon the number of processing points. actors, and the extension use cases which emerge from that particular use case.We conducted a survey to get the opinion from experienced software engineers and project managers in different software houses. We had distributed the questionnaire which primarily contained the questions to ask about the time needed to develop different types of use case as depict in the table 3. We have processed the survey data and have obtained the average time for each category of the use case.Hence we can sum up the total number of inception points and can calculate them by the number of hours required for each type of use case. Summing up the time required in hours for each type of use case can then further give us the total number of hours required to build inception points.Section 4Design Phase Size and Effort EstimationObject design model and behavioural model are produced during the design phase. We can estimate the size of each model alone and can sum the effort to obtain the total design phase effort. We can identify the Design Points, therefore we can add the weight associated to each design point and hence can measure the size and effort of that particular design point. This gives the lower level g ranularity to perceive the effort and size of each possible system feature to be designed. Hence further gives us tighter grip on the project progress.Following can be the possible design pointsEntity classes frontier classesControl classesSystem de authorshipSystem integrationAggregation / composition of objectsGeneralization / specialization of objectsObject interactionInterfacesApplication logic4.1Object Design Model Size and EffortThe main artifact of the Object model is class diagram.Class diagram is comprised of several entity, control and boundary classes. If Entity race diagram has already been produced then the effort can be fall as persistent object are already been identified. Further more each type of classes need to be designed very cautiously as control classes depict all the processing and interaction responsibilities among the classes. Where as boundary classes are responsible for the interfacing with either other system components, users, or external system for el ectronic data interchange. We declare each class to be a design point. A class in the system primarily depicts a systems object which interacts with other objects in systems environment. Hence a class does not dangle into a void but have solid connections and interactions with other classes that must be very accurately and rightly designed. Therefore we can categorize the class based on the complexity of their design. A class would be difficult to design if it has many associations, aggregations, generalizations, functionalities, overloading, reverse etc.Table 4 depicts the parameters to judge the complexity ratio of any class to be designed therefore the effort would be relevant to the complexity ratio.Complexity RatioNo of Associations No of InteractionsNo of MethodsNo of InterfacesTime needful(Hours)LowNoneNone 1-51 22 forteSingleSingle5-10 2 5 5 mellowedMultiple Multiple10-205 108Table 4 class categories for design complexityOur conducted survey tells us that based upon th e complexity ratio any class can take 2, 5, or 8 hours for designing. Remember that this time is for design of the class but coding can take extra effort in the coding phase. Therefore if we can obtain the total number of design points and multiply them with the hours required to get the total hours required for the entire class diagram.4.2Behavioral Model Size and EffortBehavioral model comprises of different diagrams which depicts the state, interaction of different classes with each other and the sequence of activities performed in the system to achieve any objective or perform business function. These diagrams are sequence diagram and state transition diagrams mainly.We declare each of these diagrams to be the design point as it is very essential to trace the possible states of the system so that a good design can be obtained. Whereas the sequence diagrams is the most forward-looking diagram that shows the complete step by step functionality and participating classes. But if th e functionality of the existing system has been well understood then creation of sequence diagrams become easier. Our surveyed data reveals the facts that each of these diagrams can be different in complexity level i.e. low, medium, high. Parameters involved for determining the complexity level are summarized in table 5 below.Complexity RatioState chart No of StatesNo of Transitions / EventsNo of Activity of StateNo of Actions associated with statesTime Required(Hours)1-51-51-51-535-105-75-75-7510-157-107-107-108Sequence DiagramNO of Classes No of ActorsNo of Events No of Control, boundary Entity ObjectsTime Required(Hours)1-51-51-51-535-105-75-75-7510-157-107-107-108Table 5 Complexity parameters for behavioral model diagramsWe perceive each of such diagrams as design point and can sum up the total number of hours required for each to obtain the total size and effort estimate to develop behavioral model.4.3Data Model Size and EffortMainly an objective is set to achieve an Entity affinity diagram to depict the over all database design for the entire software system. E-R diagram itself involves several steps to be carried out. The size of database model itself may relate to the type of software project. Embedded software may not be using any large data base but may work using few files available in the read only memory. Whereas organic and semi detached software projects may require the data to be accessed from large databases. Complexity further increases when database has to be distributed. For the time being we do not discuss about distributed databases and leave it for our emerging work. Therefore we aim to estimate the size of conventional database to be built.The following table 4 summarizes the parameters that would affect the size of the database.Complexity RatioNo of Entities No of RelationshipsNo of AggregationsNormalization DegreeQuery JoinsLow10-205-101-51-310-15Medium20-3510-205-10 1-315-25High35-50 20-4010-201-525-50Table 6 Complexity parameter s and Ratio to develop E-R ModelThe larger the number of entities to be designed, larger the database size increases. It is time go through task to identify the persistent objects (i.e. entities) in the system. Then to design its pass judgment set. Different types of attributes i.e. composite, derived and multi-valued attributes are difficult to design and to decide that which entity would be the best suitable place for any particular attribute.Based upon the complexity ratio we had conducted a survey to know that how much time and force-out is required to build the E-R model. We have analyzed the data and got the average time and no of personnel required to develop E-R model.Complexity Ratio eld RequiredPersonnel RequiredLow 7 101 2 Medium 10 251 3High 25 401 5Table 7 Required Effort for E-R modelWe have considered the flexibility range in the number one of the activities as well, therefore have concluded the time and personnel requirement in to range of lower and upper l imit.Section 5.Coding phase Size and Effort estimateMuch work has been done to focus at the code phase effort and size estimation. Mainly Constructive toll Model and Use case Point method strive cloggy to achieve this objective. But still there is room for the refinement. But as our main objective was to talk about the other phases e