When evaluating the quality of a construction project, we will look at two ways to judge quality: one is subjective, and the other is objective.
Objective quality rating focuses on the proven physical properties of the material used, such as those tested in a lab for civil, mechanical, electrical, or architectural materials.
Subjective quality rating focuses on the conceptual properties of a building, such as its aesthetic appeal, opacity, colour, etc.
Speaking from a quality personnel point of view, I had to admit that I would be 'happy' if all construction quality evaluations at a certain construction site would utilize objective quality evaluation. This will enable all parties (whether contractors, designers, or clients) to agree on the result of the quality rating and reduce argumentation over the outcome of the evaluation. In conclusion, while objective quality rating is preferred in most cases, subjective quality evaluation should still be taken into consideration especially when evaluating the aesthetics of a building (painting colour opacity, cleanliness, etc)
However, whatever rating type we use on, before we are invited to or conduct a joint inspection with a contractor's, consultants, or clients to ascertain any part of testing either conducted at a laboratory or in-situ, we shall identify what the grade of the test is and what the acceptance criteria are.
To simplify, let's use a simple analogy to discuss our ambient climate. Imagine your friend who lives in the North Pole calls you and asks about the weather in Malaysia. You say it is hot, but their understanding of hot may be different from ours. To provide a clearer view of the ambient climate in Malaysia, we need an objective rating. However, before we can establish that rating, we need to define three criteria: -
What is the parameter - temperature?
How are we going to measure - thermometer?
What is the measurement unit - Celsius?
Thus, providing the ambient temperature in Malaysia, measured with a thermometer as a sensor and expressed in Celsius, can offer a comprehensive understanding of the Malaysian climate, even to individuals who have never visited our country.
Therefore, in the field of construction, when determining the strength of concrete (as an example), we utilize the aforementioned criterion which use the same concept as above: -
What is the parameter - concrete strength?
How are we going to measure - compressive strength according to BS EN 206? (just an example)
What is the measurement unit - MPa or kN/mm2?
In quality viewpoint, we include an additional criterion known as acceptance criteria. This criterion serves to determine the distinguishing features of the product, or the level of skill demonstrated by the contractor.
4. Acceptance criteria - 30MPa or 20MPa (as mentioned in drawing or specification or Bill of Quantity)
These criterions will later serve as the primary factors for establishing the Inspection and Test Plan (ITP), which we will discuss in more detail later.
The acceptance criteria required a thorough reference to the relevant specification, standards, or code of practice to identify the precise acceptance criteria for the work or test. Whatever reference we use, please keep in mind that it must be relevant to the contract documents, because those form the basis of agreed-upon quality measurements for the whole project between contractor and client.
Have you identified the inspection and test points for your construction project? Secondly, do you know what is the parameter for your inspection? And, finally, do you know what the acceptance criteria are for the parameter that you are going to conduct or witness? Is the acceptance criteria mentioned somewhere in the relevant specification, standards, or codes of practice?
Good