Comparing RCA Tools
One of the key drawbacks of the five whys approach is that most problems are not explained by a single causal factor. In applying the technique, it is common to discover that there are multiple answers to a single question. By focusing on only one answer, it is possible that a root cause will be discovered that only provides a partial understanding of the problem. Cause and effect analysis (sometimes called Ishikawa analysis or fish-bone analysis) provides a means of plotting these multiple root causes in a way that allows the analyst to truly understand all the sources of risk, as well as the interdependencies among the causal factors.
Once the causes and their effects are fully mapped out, it would be possible to identify the key drivers of risks that impact the problem. Using techniques such as Pareto analysis (where 20 percent of the effort should deliver 80 percent of the results), it would be possible to prioritize the issues and then make informed choices about which risks, and in which order, the agency would choose to address in dealing with the problem.
Failure mode, effects, and criticality analysis (FMECA) is a process that was developed by, and used extensively in, process-driven and engineering industries. It is an extension of the failure mode and effects analysis (FMEA) technique, which is designed to identify the inherent or root causes of risk associated with a process or system. By adding in an analysis of how critical these risks are, risk owners are able to identify those high-consequence and/or high-likelihood risks that they should address as a matter of priority.
Considering our influence diagram, we can see that the lack of police patrol presence impacts the greatest number of other forces. This conceptually makes sense given what criminology tells us about preventive policing. Where there is a lack of obvious police presence, individuals feel less inhibited about conducting activities that they would otherwise hide or not carry out, compared to how they would act in higher-scrutiny places. Equally, we can also see that the more empty homes and businesses there are in a neighborhood, the more safe places there are for crime to occur.
In this case, the most effective solution is likely to be an increase in visible policing in the neighborhood (something that the police can control), coupled with a community revitalization effort to fill the empty houses and businesses (most likely led by the community itself) in order to remove or reduce the number of places where criminals feel comfortable operating.
Combining the force field analysis and influence diagram techniques is often helpful, as it enables a fuller understanding of the factors in play to be developed. It also helps to develop an understanding of how and where existing pressures can be leveraged to achieve the desired outcome.
-  Pareto analysis is a technique used to identify those courses of action or options that are likely to deliver the greatest benefit. It is based on the theory of diminishing returns, and can be referred to as the 80/20 rule, where 80 percent of the value is seen to be delivered through the use of 20 percent of the available resources. See, for example, Suzanne Turner's description in Tools for Success: A Manager's Guide, where the technique is referred to as "vital few analysis." 22