Assessing the risks by quantifying them should be done. Even with qualitative risk assessment, quantifying is still important since risks need to be prioritised.
Risk assessment can be qualitative or quantitative. Perform qualitative and perform quantitative risk analysis are two processes within the project risk management knowledge area, in the planning process group. While qualitative risk analysis should generally be performed on all risks, for all projects, quantitative risk analysis has a more limited use, based on the type of project, the project risks, and the availability of data to use to conduct the quantitative analysis.
Qualitative Risk Analysis
A qualitative risk analysis prioritises the identified project risks using a pre-defined rating scale. Risks will be scored based on their probability or likelihood of occurring and the impact on project objectives should they occur.
Probability/likelihood is commonly ranked on a zero to one scale (for example, .3 equating to a 30% probability of the risk event occurring).
The impact scale is organizationally defined (for example, a one to five scale, with five being the highest impact on project objectives - such as budget, schedule, or quality).
A qualitative risk analysis will also include the appropriate categorization of the risks, either source-based or effect-based.
Quantitative Risk Analysis
A quantitative risk analysis is a further analysis of the highest priority risks during a which a numerical or quantitative rating is assigned in order to develop a probabilistic analysis of the project.
A quantitative analysis:
- Quantifies the possible outcomes for the project and assesses the probability of achieving specific project objectives
- Provides a quantitative approach to making decisions when there is uncertainty
- Creates realistic and achievable cost, schedule or scope targets
In order to conduct a quantitative risk analysis, you will need high-quality data, a well-developed project model, and a prioritized lists of project risks (usually from performing a qualitative risk analysis).
Reference: CIPS study guide page 143-144
LO 3, AC 3.3