Estimation Technique

Below Project Estimation Rules should be recalled when doing Estimation of a Testing Project: 

 

• Software requirements are considered for Estimation
• Expert judgment matters for Estimation of the Project
• Previous projects matter for Estimation of project
• Metrics helps in Estimation
• Past should never be ignored while doing Estimation
• Recording of Estimation is indeed essential
• Tools should be used while doing Estimation
• Estimation should continuously be verified
• Risk factors should be covered in Estimation

1st Rule: Software requirements are considered for Estimation

Software requirements are indeed essential for test estimation as it is based completely on what would be tested. The development team has much involvement in the software requirements as compared to the testing team and the requirements are mostly established by the development team. When all the estimation are done related to the project cost, duration of the project then the development team asks the testing team that how much time will be required by them in order to complete the testing of the application. The answer given by the testing team is considered for the SDLC process.

Testing team plays a vital role in estimation of the project because testing is an essential part of SDLC. Testing application, one can deliver a bug free application to the client.

2nd Rule: Expert judgment matters for the Estimation of the Project

The testing team classifies the requirements before estimating them in the following categories:

• Critical: The development team has slight knowledge in how to implement it;
• High: The development team has worthy knowledge in how to implement it but the task is not easy at all;
• Normal: The development team has decent knowledge in how to implement. 

The expert opinion in each requirement suggests how long it would take for testing them.  The categories would eventually help the experts in estimating the effort for testing the requirements.

3rd Rule: Previous projects matter most for Estimation of project

Previous project knowledge and experience are used for the estimation of the project. If new project is introduced then its estimation is based on similar projects which have been executed previously. 

4th Rule: Metrics Helps in Estimation

Organization should create an Organization Process Database which is also referred as OPD, where the project metrics are recorded and referred for future projects.

5th Rule: The past should never be ignored while doing Estimation

Spreadsheets and Old process is still used by the testing team in order to estimate the project completely. If new rules are introduced during the process then the testing team follows that and at the same time compares the old process too so as to get complete idea in test Estimation.

The results which come from the new estimate process should be faster and cheaper as compared to the old process and in percentage of 20 to 20%. If different percentage are measured by the testing team then they go back to the old process to check whether they are missing something during the process or not.

 6th Rule: Recording of Estimation is indeed essential

During testing of the process all the results should be recorded in order to refer it for future projects. It is also beneficial when requirements of the projects change and hence the recording will eventually help the testing members in estimating the project. This will help testing team to not return all the steps again and will further help in taking same decisions. It also gives the opportunity to test the estimation before making any changes to it. 

7th Rule: Tools should be used while doing Estimation

A spreadsheet containing metrics eventually helps reaching the estimation as quickly as possible. The spreadsheet will calculate it automatically hence giving ease to the team members. It also helps in tracking the duration and time of the projects. 

Risk Table, and free notes should be included in the template and need to be filled in the tool. These tools also help in showing different options for testing which actually aids the customer in deciding which types of test he needs practically.

8th Rule: Estimation should continuously be verified

All estimation should be verified in a certain period of time.  Along with this, another spreadsheet for recording the estimations should be created.  The estimation is compared to the previous ones recorded in a spreadsheet so as to see if they have similar trend.  If the estimation has any deviance from the recorded ones, then it is indeed essential to a re-estimation of the entire project.

9th Rule: Risk factors should be covered in Estimation

Product down time, resource unavailability, skill improvement and learning capability are some of the risks that should be covered in test estimation.

Scenario for an Estimation:

Assume you have a project and you have estimated that it will take a 10 person team 300 days to complete. (3000 workdays – Sunny day scenario)

Knowing that there are 365 working days in a year (52 weeks x 5 days), without holidays, means that the project, at best, will take 1.13 years or 13.6 months to complete.

Suppose the average year includes 12 days company holidays (total impact = 12×10 people = 120 daysx1.13years = 136 days) and average employee takes 4 sick days and 3 comp days off a year (total impact = 7 x 10 people = 70 x 1.13 = 79)

Average employee takes 7 work days of vacation a year (total impact = 7 x 10 people = 70 x 1.13 = 79)

Suppose also that each employee drops 3 days out of each year for training (30 days)

Total duration change due to employee holidays, sick time, vacation and training = 136+79+79+30=324

Total workdays for the project is now 3000+324 = 3324 or a 10.8% increase in duration (300 day schedule is now 333 days or 15.1 months.)

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