AN INVESTIGATION INTO DESIGN ERRORS AND IT’S IMPACT ON INITIAL COST OF A CONSTRUCTION PROJECT. A RESEARCH PROJECT MATERIAL ON QUANTITY AND SURVEYING
1.1 BACKGROUND OF THE STUDY
When asked to define “design error,” not all disciplines in the construction process agree on a common definition. Depending on which discipline you address, the owner, the designer or the contractor there will be a common understanding surrounded by varied conclusions, “a mistake.” From the basic definitions of “design” and “error” we conclude that a design error is a deviation from a drawing or specification, also including omissions and ambiguities. It is the seriousness of this error that must be considered to determine its consequences on the overall outcome of the project One of the most important challenges facing management today is controlling the all too frequent cost and schedule overruns that effect the construction industry (Diekmann and Thrush, 1986). One of the major issues to control growth in project costs and time is the reduction of design errors.
The owner, designer and contractor all have different interests in, or uses for the design of a facility. But what they do share is the commitment to complete the project safely and within a given budget and completion time. There are many initiatives being conducted to control the growth of cost and schedule within the construction industry.
The major issue is “accuracy of the drawings,” or the number of design errors, omissions and ambiguities within the plans and specifications that affect the quality of the facility. Inadequacies in the plans and specifications are the major causes of changes to the contract So much emphasis is placed on the issue of time and cost that quality takes a back seat The quality of the project depends on the conformance of the objectives and requirements from the owner. An informative quality management technique will provide an agreement to procedures and definitions among the principle parties for the project. Since design errors have an impact on the outcome of the effectiveness of the contractor’s effort on the project it is essential that all parties determine what the definition of a design error should be. When asked to define design error, not all disciplines in the construction process agree on a common definition. From the basic definition of design and error it can be determined that a design error is a deviation from a drawing or specification. It is the seriousness of this error that must be considered to determine its consequences on the overall outcome of the project
1.2 STATEMENT OF THE PROBLEM
Design errors indicate the total design in-effectiveness of a project. Major design quality problems occur during construction when errors, omissions and ambiguities in plans and specifications become evident (Davis and Ledbetter, 1987). This statement directs that the inadequacies in the plans and specifications are the major causes of changes to the contract. There have been extreme examples of design errors such as numerous building collapse in Nigeria – projects that have wrought disaster after the construction are completed. These are examples of design errors that escaped the close scrutiny of all parties. One or two major errors that can be corrected with only cost considerations and little effect on the schedule can impact projects. The projects that really suffer are those with many small errors (design, rework or change of scope) which when finally added up cause major impacts on the cost and schedule growth.