1. Recent trends in estimation methodologies
- Sharing of experience
Nagaraja Gundappa
Head, Execution Excellence group
Talent Transformation
Wipro Technologies

2. Overview Experience with current methodologies for web applications
Cocomo
Function points
Use case points
New paradigm in effort estimation – open estimation methodologies
Need for open methodologies
Characteristics of open estimation methodologies
Sample estimation methodologies
Experience with MVC Points
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3. Current methodologies…
Cocomo
Focuses on estimating effort given the size of application in lines of code
Does not offer any method to arrive at the size in lines of code
For web applications, given the complexity of environments, it is extremely difficult to estimate the size in lines of code given high level requirements
Usage level is almost zero for estimating for web applications
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4. …Current methodologies…
Function points
Views an application as consisting of a set of functionality defined by transactions. Size of transactions determines size of application
Complexity of transaction is determined by amount of data involved in the transaction
Visualization of application not in line with OOSE
Not easy to bring in new complexity factors
Not easy to validate size (FP) to effort conversion
Not widely used for estimating web applications
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5. …Current methodologies…
Use case points
Views an application as consisting of a set of use cases.
Complexity of use cases is determined by complexity of actor and number of transactions involved in the use case
Visualization of application in line with OOSE; more relevant for web applications
Writing use cases currently is very subjective.
Having one use case with many transactions v/s having nested use cases
Not easy to bring in new complexity factors
Not easy to validate size (UP) to effort conversion
Not widely used
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6. Current paradigm Summary of current estimation methodologies
Generic – applicable for all technologies
Because the sizing units are abstract and not specific to a technology, it is difficult to visualize the application in terms of the sizing units
Because sizing units do not directly correspond to code units, it is cumbersome to validate the conversion of size to effort at a unit level.
Closed – involves empirical equations in arriving at size
Difficult to add new complexity factors by the users
Difficult for organization to adapt and take it through continuous improvement with user level customization and optimization
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7. New paradigm Open estimation methodologies A new trend
Standardize work break down elements into sizing units
Define complexity factors for classifying sizing units
Define effort norms of sizing units of various complexities
Specific – applicable to specific technologies and application types
Sizing units specific to technology / application type. Easy to visualize
Sizing units correspond to code units
Open – does not involve empirical equations in arriving at size
Easy to add new complexity factors by end users
Possible for organizations to adapt and take it through continuous improvement with user level customization and optimization
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8. New paradigm - methodologies
Some methodologies in the new paradigm
Template points
Used for portal development by implementing content management packages
Data points
Used for data migration projects
Interface points
Used for Enterprise Application Integration projects
MVC Points
Used for J2EE and .Net development projects
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9. New methodologies – closer look
Template points
Customization of content management products essentially involve customizing pre-built templates
Complexity of each template is determined by difficulty involved in customizing it
Templates classified into simple, medium and complex based on number of hooks and complexity of processing involved in each hook
Data points
A table / file is a sizing unit
Complexity of structure such as if the data is nested or not determines complexity of unit
Complexity of processing / transforming data while migrating
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10. Interface points Interface points
Alternate names are integration points and message points
One interface point is one link between a source system and a destination system to carry a set of related data (message)
Ex:- an interface between works management system (Oracle application) and Customer management system (A CRM application on SAP) for booking appointments is one interface point.
An interface can also be viewed as an object involving a specific group of fields and defined operations
This is classified into simple, medium and complex based on
Complexity of the data
How many hierarchies?
Complexity of the technology to establish connectivity / build adapters
Processing (operation performed on data)
Straight forward mapping between fields to fields
Looping through data fields for mapping between source and destination
Any processing / transformation to be done
More than 250 applications have used this successfully
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11. MVC points
Overview
Based on the architecture pattern called Model-View-Controller (MVC)
Most web applications, especially J2EE and .Net applications follow an MVC pattern
An application is viewed to be consisting of a number of use cases each realized through a set of models, views and controllers
The models, views and controllers (MVC Points) are classified into simple, medium and complex and have defined effort norms
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12. MVC pattern For those new to MVC patterns…
Mapping of MVC pattern to J2EE technology
Model
View
Controller
JSPs
Servlets
EJBs
DBMS
User
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13. MVC Points - steps
Step 1: Assume a Model-View-Controller (MVC) pattern for the application.
Step 2: List all the Use Case titles
Step 3: Identify the View Classes, Model Classes and Controller classes for all use cases
Step 4: Categorize each view, model and controller class as Simple , Medium or Complex.
Step 5: Add the Models, Views and Controllers in each category
Step 6: Multiply the number of models, views and controllers by corresponding effort norms. This step provides the Coding and Unit Testing (CUT) effort in person days for each category of MVC points.
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14. …Steps
Step 7:Add the effort of each category to arrive at the CUT effort for the whole application
Step 8: Multiply the CUT effort by 2.5 to arrive at the life cycle effort
Step 9:Check if any other miscellaneous tasks outside the purview of MVC that have to be estimated and carry out the estimate using WBS
Step 10: Determine project management effort and Buffer
Step 11: Add efforts of steps 8, 9 and 10 to arrive at the final effort estimate for the project
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15. MVC Points - Samples Complexity indicators A complete estimation sheet
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16. MVC points – Validation results
Re estimations
An application for a publishing industry company
Effort originally estimated by the team = 11 person months
Actual effort = 16 person months
Effort re-estimated using the MVC Points methodology = 18 person months.
31% deviation in the original estimates and 12% deviation in re estimation using the MVC Points model
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17. … Validation results …Re estimations
An application for a company in manufacturing industry
Module 1:
Effort originally estimated by the team = 120 person days
Actual effort = 180 person days
Effort re-estimated using the MVC Points methodology = 198 person days.
33% deviation in the original estimate and 10% in re estimate
Module 2
Effort originally estimated by the team = 140 person days
Effort re-estimated using the MVC Points methodology = 169 person days
22% deviation in original estimate and 6% in re estimate
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18. … Validation results Comparison of estimate v/s actual effort
An application for a company in retail industry
Estimation was prepared using MVC Points methodology and the estimate was compared with actual effort after project completion
Estimated effort = 756 person days
Actual effort = 786 person days
The deviation between the estimation and actual effort is - 4%
The effort under run was attributed to over skilled team
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19. MVC points – Merits and demerits
Intuitive to use for web applications
Sizing units are based on actual coding units that will be developed
Maps well to the object oriented paradigm
Possible for organizations to adopt, customize and optimize
Complexity factors do not have empirical equations and hence end users can add new complexity factors easily
Effort norms per sizing unit can be easily verified as sizing units are coding units.
Demerits
Limited applicability as methodologies are specific to technologies
Yet to have any standard bodies supporting the methodology
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20. Conclusions
‘One size fits all’ paradigm seems to be inadequate. Most current methodologies belong to this paradigm
We are witnessing the emergence of many open methodologies
These are semi formal methodologies developed by practitioners
Local to specific technology and application type
User level customization and optimization is possible
MVC Points is the first such open methodology to be articulated formally
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21. Thank You
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22. MVC Design Pattern
MVC is an architectural pattern that is used when developing interactive application. Any interactive application can be categorized into:
View Classes which handle the GUI
Model Classes which can be entity classes interacting with the database tables of the application or the business logic classes
Controller classes which communicate between the View and Model Classes.
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23. MVC and Internet applications
Typically in internet applications User interfaces change often, look-and-feel being a competitive issue.
The same information is presented in different ways.
The core business logic and data is stable.
So model classes would not change often but view classes would
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24. Advantages of MVC Pattern
Separating Model from View (that is, separating data representation from presentation)
- easy to add multiple data presentations for
the same data.
- facilitates adding new types of data
presentation as technology develops.
- Model and View components can vary
independently enhancing maintainability,
extensibility, and testability.
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