Estimating based on Work Breakdown Structure (WBS)

The Work Breakdown Structure (WBS) is an estimating approach based on splitting up the activities into partial activities up to a level of detail at which the required time per activity can be estimated. By adding the time required for the partial activities, the total required time is calculated. 

The table below shows the number of hours per quality characteristic. For quality characteristics where the strategy matters, this is shown. The hours are derived from actual practice. Please note that the experience base and therefore how hard the figures are differs.

Levels of hardness are: 

• Hard: experience from multiple projects, confirmed on the basis of multiple sources
• Experience: based on a few sources
• Soft: an estimate by experienced test consultants.

Practice demonstrates which factors have the greatest impact on the definitive number of hours. These factors are shown.

Strategy = ∨, ∨∨ or ∨∨∨ (low, medium, high risk/importance)

Quality Characteristic	Strategy	Hardness estimation	Hours	Important factors for variation in size
Manageability Installability		soft	24
Security	∨∨∨	experience	80	Minimal, hour box
Effectivity	∨∨∨	soft	350	Incl. hours of users
Continuity	∨∨∨	N/A	–	Depends on the duration of shadow production
User-friendliness	∨	hard	70	Size of application (limit 15/100 screens) Scope of research question (limit: several subjects)
User-friendliness	∨∨	hard	80
User-friendliness	∨∨∨	hard	130
Performance, online	∨∨	hard	192 – 224	Low: 15 user tasks High: 40 user tasks Complex database
Portability	∨	soft	28
Economy	∨	soft	28

Please note: The table above does not include hours for e.g. setting up a usability lab or selecting test-support packages. The starting point is that the required facilities must be available.