1. Rule number one: only some of the moves result in complaints. People usually do not write about their positive moving experiences, and if they do - those reviews tend to be treated with suspicion. Negative reviews, on the other hand, are welcomed and tend to be very pictorial, and often get referred to from many sources.



2. The average daily number of moves performed by a moving company directly correlated to the number of trucks it owns. For that purpose we use the number of Power Units owned by a mover as specified in his SaferSys.org report. From our experience the average number of moves performed daily over a calendar year is approximately half the number of trucks owned by the mover. Thus, if a moving company officially owns 6 trucks we assume it performs 3 moves a day (or 1095 moves a year).


3. Only one fifth of serious complaints end up listed with the BBB. There are many reasons for that - one of them is the fact that the issues get settled before reaching boiling point, another - simple fact that people don't know they can do it. Whatever the reasons are from our experience four out of five serious complaints do not reach BBB. As a result we multiply the number of complaints listed on BBB in the last 3 years by 5 (and then divide by 3 to get yearly number). Example: if a company has 6 complaints with the BBB for the last 3 years then we assume it actually has on average 10 serious incidents a year (or more - read next rule of thumb).



4. Considering information from other sources. Since BBB is not the only authority for complaints and in order to stay on the safe side we add into the formula the input we find in other sources such as MovingScam.com, RipoffReport.com, Epinions.com and others. Rule of thumb: we add all unique negative reports on moves performed by the mover in the last 3 years and multiply by 2.5. For example, if we find 5 unique negative reports over the course of 3 years on the consumer sites, and 6 complaints on the BBB we assume the mover has on average 14.2 serious incidents a year.



5. The number of less serious incidents is ten times higher then the number of more serious incidents. Again, from our experience it is safe to assume that less serious incidents (such as late delivery, one or two damaged items, few lost of crushed moving boxes, reasonably higher final price, etc.) take place ten times as often as the serious incidents. Therefore, if the mover has 14.2 serious incidents then we assume it has 142 less serious incidents a year. To finalise, this mover has 156.2 more or less serious incidents a year.



6. It is usually safer to move with agents of big van lines then with independent movers. Lets assume you have the choice between independent company A and company B that is an agent of a major nationwide van lines, and those two companies have the same credentials and offer you the same deal. In that case company B has the advantage and would be considered a safer choice by us. There are many reasons for that, for example each van line requires their agents to follow strict set of rules and they periodically audit those companies performance. Also, when moving long distance it is safer to use major van lines because you will know for sure who will deliver your items.
   
   For the purpose of SOUR calculation agents of van lines will enjoy a 20% decrease from the number of unsatisfied customers.
   
   
7. Young companies are riskier then old ones. A company that is long time in business would be considered less risky then the one that was just launched. There are many reasons why we would include this factor into the formula. For example, many scammers who had to shut down their F-rated companies often open new "clean" companies and resume their operations. To be considered safe a company needs to be in business at least for few years.
   
   We use the following rule of thumb: if a company is less then a year in business it is penalized by 30% increase (in the number of unsatisfied customers), less then 2 years - 20% increase, less then 3 years - 10% increase, between 3 and 5 years no penalty, between 5 and 10 - a 10% bonus decrease, and finally over 10 years a 20% decrease in the number of unsatisfied customers.
   

SOUR (percentage) = (1-((I*(1+A+Y))/M)) * 100

1. SOUR 99.9% and up


2. Company has to be at least 3 years in business


3. SaferSys.org Safety Rating has to be at least "Satisfactory" (usually meaning that both Vehicle and Driver out-of-service rating are below the national average, but not necessarily)