Software Estimation Models

Effort and Schedule Estimation for Software Development

COnstructive COst MOdel II (COCOMO II) is a software parametric model to estimate the cost, effort, and schedule when planning software development activities. COCOMO II.2000 is the latest major extension to the original COCOMO81 model published in 1981. 
It is made up of three submodels, each one offering increased fidelity the further along one is in the project planning and design process. These submodels are called the Applications Composition, Early Design, and Post-architecture models. 

One can find more information on the following reference page of COCOMO.

According to the book below, I created a calculation sheet that can be downloaded.

(Boehm, B. W.; Horowitz, E.; Madachy, R.; Reifer, D.; Clark, B. K.; Steece, B.; Brown, W. A.; Chulani, S. & Abts, C.
Software Cost Estimation with Cocomo II
Prentice Hall PTR, 2000)

Use Case Points
Effort Estimation for Software Development

Specifications are often based on UML and could be characterized as use case oriented. Therefore we are looking for estimation methods that directly calculates efforts by counting use cases. An estimation method based on Use Case Points (UCP) fulfils the most suitable requirements of a use case orientated top-down estimation method. With UCP it is easy to learn for experienced software engineers and results in efficient effort estimations.

According to the article below, I created a calculation sheet that can be downloaded.

(Anda, B.; Angelvik, E. & Ribu, K.
Improving Estimation Practices by Applying Use Case Models
PROFES '02: Proceedings of the 4th International Conference on Product Focused Software Process Improvement, 
Springer-Verlag, 2002, 383-397)