Defects in Design and Construction

Some are clear in that they are errors or mistakes. Other design defects are less clear; they are missing information, invalid assumptions, clashes between components, misunderstood requirements, and/or poor choices.

A Request for Information is a defect. It is a defect because it arises from missing information, information that is inconsistent, or information that is wrong. If the drawings, specification, and contract were complete, unambiguous, and error free then except for the unforeseen, RFI would not exist. Yet they do exist, regarded as inevitable, and for any project, resources cost will be budgeted for to deal with them. Apart from errors and mistakes a common belief links these together - the mantra of "sort it out on site". Is any design problem so intangible that it cannot be resolved in the design office? One reason given openly for this is the lack of design resources and time. Yet these shortfalls cost much more to resolve on site.

Womack in "The Machine That Changed The World" explores the differences between Japanese, US and European car manufacturers at the beginning of the 1990’s. One reason why costs of car production in Japan were a 1/4 of those in Europe at the beginning of the 1990's was the "army" of technicians at the end of the production line in European plants fixing problems with the vehicles that rolled off, and there were many. Manufacturers held on to the belief that they were craftsmen and that luxury cars were believed different from mass production vehicles. This held back the adoption of efficient production systems and Womack found that there was little difference between mass production and luxury ranges from a production perspective. There were, in fact, except in highly niche low volume producers, no craftsmen in the industry.

At the time, in the US and Europe defects were regarded as inevitable along with the cost of fixing them. A German plant was spending more fixing defects than a Japanese plant was spending to build a defect free car. Some in the car industry refused to accept this maintaining that the Japanese had hidden plants where the defects were sorted out of sight. These did not exist, and for US and European car makers, it became compete or die.

Construction and Design is at a similar crossroads today. It can continue to believe that defects and waste are inevitable, or it can work to eliminate them at source. It can also continue to believe that construction is a craft industry and not a production environment; albeit one where the workers go to the work rather than the work come to them. It can also continue to see projects as one off prototypes or deliver to owners the benefit of standardisation and prefabrication.