A good bread should be judged by its volume, bloom, shape, colour, texture, sheen, moistness and flavour. In general, one should examine the external area and the internal (crumb) area of the bread.
Bread faults can occur as a result of a series of small faults interacting together. Some faults may be inter-related yet others are independent. Flour varies in grade, in gluten content and quality. Colour also varies and so does the maltose content. In my bakery, when examining the faults in a loaf of bread, the temperature and timings, methods of manipulation, addition of ingredients, errors in setting and timing of machinery (mixer and oven), are all taken into account.
Because of the complexity of bread production, many things can go wrong. To remedy common bread faults, check the following link for possible causes and correct your procedures.
http://www.bakeinfo.co.nz/files/file/91/BIRT_Bread_Faults.pdf
Images via http://www.sbakels.co.za/breadfaults.htm