Cost Estimation Methods
G Different Options for Cost Appraisal
Expert View Method
Qualified judgment methods involve seeing software expense estimation qualified or a number of the experts to work with their encounter and understanding of the suggested project to travel to an estimate of its cost. In most cases, a group consensus technique, Delphi technique, is a good way to become used. The strengths and weaknesses are contrasting to the strengths and weaknesses of computer method. To get a sufficiently broad communication band width for professionals to exchange the quantity of information required to calibrate all their estimates with those of the other authorities, a wideband Delphi strategy is introduced more than standard Deliphi technique. Methods using this estimating method:
1 . Planner presents every expert with a specification and an evaluation form. installment payments on your Coordinator phone calls a group conference in which the authorities discuss appraisal issues with the coordinator every other. a few. Experts fill in forms anonymously
5. Coordinator works on and distributes a summary of the estimation on an iteration contact form. 5. Manager calls an organization meeting, specially focusing on obtaining the experts talk about points exactly where their estimates varied generally. 6. Specialists fill out forms, again anonymously, and methods 4 and 6 will be iterated for as many rounds as appropriate. The wideband Delphi Approach had been utilized in a number of research and price estimation actions. It has been very successful in combining the free go over advantages of the group conference technique and advantage of confidential estimation from the standard Delphi Technique. The huge benefits of this approach are:
•The experts can cause in variations between earlier project experience and requirements of the proposed project. •The experts can easily reason in project affects caused by fresh technologies, architectures, applications and languages involved in the future job and can likewise reason in outstanding employees characteristics and interactions, and so forth
The disadvantages contain:
•This method cannot be quantified.
•It is hard to document the factors used by professionals or experts-group. •Expert may be some biased, optimistic, and pessimistic, though they have been lowered by the group consensus. •The expert wisdom method often compliments the other cost estimating strategies such as computer method.
Top-Down and Bottom-Up Methods
Top-Down Estimating Approach
Top-down price method is also referred to as Macro Unit. Using top-down estimating method, an overall cost estimation to get the project is derived from a global properties from the software job, and then the project is usually partitioned into various low-level components. The key method employing this approach is Putnam version. This method is somewhat more applicable to early cost estimation when only global properties will be known. Inside the early stage of the computer software development, it is quite useful because there is no in depth information offered. The advantages with this method will be:
•It focuses on system-level activities including integration, records, configuration management, etc ., many of which may be dismissed in other calculating methods but it will surely not miss the cost of system-level functions. •It requires nominal project detail, and it is generally faster, better to implement. The disadvantages are:
•It often does not identify challenging low-level problems that are likely to elevate costs and sometime tends to overlook low-level components. •It provides simply no detailed basis for justifying decisions or estimates. Because it provides a global view with the software job, it usually embodies a lot of effective features such as cost-time trade off ability that is out there in Putnam model. Bottom-up Estimating Method
Using bottom-up estimating approach, the cost of every software elements is predicted and then combines the leads to arrive at approximately cost of general project. That aims at creating the calculate of a...
Referrals: 1 . Schwalbe, K " Managing Information Technology Projects”, 6th Edition.
2 . Gray | Larson " Project Management: The Managerial Process”, Out Edition.
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[Date of access: 12 Feb. 2012]
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[Date of access: 12 Feb. 2012].