Content of chap. 9
9.1 Legislative dealing with the quality of buildings
9.2 The concept of quality in construction companies
9.3 Organizational measures to ensure the quality of constructions company
9.4 Quality plan of buildings, inspection and test plan
9.5 Costs and quality of buildings
9.6 The quality of project documentation for construction
9.7 Constructions quality control
9.7.1 Ensure quality control during pre-production and production preparation of construction
9.7.2 Quality control during construction works
9.7.3 Quality control during use of the building
9.8 Construction quality evaluationy
9.9 Training of personnel in constructions quality assurance
9.10 The principles of quality management, accreditation and certification of construction companies
Cited literature |
Quality can be defined as summary properties of a product or services that reflect their ability to fully meet customer requirements (see ISO International Standard 8402).
The decisive criteria for the quality of construction is high reliability and durability of structures, high standard of user parameters and minimum costs for operation and maintenance. The process of designing construction work is actually planning phase of its quality. Quality is defined by requirements, which specify state and the builder. The primary responsibility has builder (the investor), because he is financing building and should have a basic idea of what he wants to achieve. The designer and contractor must accept these demands, but as minimum requirements, and in their approaches must respect the interests of society as a whole.
9.1 Legislative dealing with the quality of buildings
Basic rules and standards that deal with or affect the quality of construction works can be divided into two groups:
a) Directly affecting the quality of buildings:
- act no. 505/1990
coll., about metrology,
- act no. 22/1997
coll., about technical requirements for products,
- government regulation no. 178/1997
coll., laying down technical requirements for construction products
- ISO 9000 series (International Standard Organization), which unify the management system requirements and quality assurance at the international level.
b) Indirectly affecting the quality of buildings:
- act no.197/1988
coll. (full) about zoning and building code,
- Civil and Commercial Code and the Trade Act,
- act no. 199/1994
coll., about public procurement,
- act no. 17/1992 as act no. 123/1998
coll., about environment,
- act no. 125/1997
coll. (full), obout waste.
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9.2 The concept of quality in construction companies
Implementation of quality management system at the construction company requires the identification process and clear concept. These aggregate goals, objectives and work organization in the field of quality production, which was approved by the company's management and are binding on all its employees. Quality control is part of the work of the entire management.
The concept of quality must take into account the commercial, technical, manufacturing and economic strategy for construction companies. Based on this in particular:
- needs and requirements of the builder and users of construction works
- analysis of their own ability to meet those needs and requirements
- application of the precautionary principle against the principle of detecting poor quality building materials, structures and objects.
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9.3 Organizational measures to ensure the quality of constructions company
Organization of construction companies should be adapted to allow the effective operation of the system quality assurance structures. It must clearly identify staff responsible for implementing specific tasks from the area of quality in the preparation and construction.
An example of an organization larger construction firms (with more than 100 workers) to the needs of ongoing quality assurance constructions is shown in
fig.
9.1. The main responsibility here has director and trustee for quality.
Director is in matters of quality control responsible for:
- economic results of the entire company,
- implementation and control of quality management system,
- application of the latest developments in quality management,
- development of quality policy,
- education system for company employees,
- evaluation of achievements and application of conclusions in the further work.
Since the Director provides a number of other senior management duties, he appoints responsible person for quality control, known as appointee for quality.
For larger construction firms (with more than 100 employees) and large constructions is further recommended to establish a manager for construction quality.
For medium
and small firms, will
function of quality
construction manager
perform construction manager
or foreman.
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9.4 Quality plan of buildings, inspection and test plan
Decisive
basis for quality assurance
is quality plan
and its
important part - the control
and test plan.
Quality Plan of lays down
specific procedures for
the general quality assurance
on site.
Inspection and Test Plan (KZP)
determines the type of tests,
their frequency, method of
design and documentation,
responsibility, and any
other necessary information
related to inspection
and test activities during
implementation.
Site managers, foremen and leading work teams, as well as manual workers called self-test ensures the quality of work performed on site by KZP.
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9.5 Costs and quality of buildings
The quality of construction work affects the amount of the cost of its acquisition. Experience shows that expenditure on repair of poor quality products are usually higher than the cost of preventive care for the quality of production. Analysis of the cost assurance construction production quality is an important basis, which allows to assess the overall effectiveness of quality management in construction company, and focus attention and resources on problem areas in providing quality construction work.
Direct costs on quality of construction can be divided into three groups:
- costs of poor quality construction work or its parts
- costs of inspection and testing of the quality or its parts
- costs of quality prevention.
The cost of poor quality construction work will arise, if the building or its part does not meet standards, project, or contractually agreed requirements of the client and must be negotiated axle. Supply company brings financial loss, but also worsens their position in the market by loss of confidence of customers.
The cost of inspection and testing quality of construction and parts are typically costs for controlling used materials, inspection and testing of construction works, structures and components. It is therefore a cost of input, process and output control of construction production processes.
The cost of prevention is related to the design, use and maintenance of quality assurance structures. The effectiveness of these costs take effect after a certain time.
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9.6 The quality of project documentation for construction
The resulting quality of new construction also affects the quality of project documentation. Incorrect design construction solution of objects does not satisfy customer, even if it was done in high quality. For example. according to a survey in Great Britain represents share of project of low-quality production up to 40% [5].
Project documentation must respect the terms of the quality of compliance with these particular features of the object:
- mechanical strength and stability
- fire resistance
- hygiene, health and environmental protection
- safety in use
- protection against noise
- energy savings.
In addition to providing these basic requirements design documentation must conform to the technical, operational, economic and aesthetic intentions of the builder. It must be complete, unambiguous and understandable. The designer should be aware that the project must allow smooth implementation of project and its use. Absence of this approach leads to repetition of some errors and to stagnation of planning improvement.Cooperation with the executor of the building is appropriate and is often necessary, especially in terms of choice of appropriate technologies. Many problems can thus be resolved before agreeing to the project documentation.
The designer (as author supervision) should has permanent access to site and check the compliance of works with the project. Possible changes to the project must be agreed and recorded.
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9.7 Constructions quality control
In accordance with the technological process of implementation of construction is control divided into:
- input (pre-production)
- interoperating (in-process of construction)
- output (post-production).
9.7.1 Ensure quality control during pre-production and production preparation of construction
During pre-construction preparation are clarified supplier and customer relationships and takes place approval of project documentation. This creates the basic requirements of future quality of the works. The purpose of inspection is:
- assess project documentation with respect to compliance with laws and regulations and in terms of the applicable standards
- verify the construction solution of objects
- examine the suitability of proposed materials and technological procedures
- assess the needs and possibilities of controls during construction and create conditions for them.
Construction contractor has an opportunity to influence design solutions and contribute to the creation of quality construction project.
9.7.2 Quality control during construction works
Control is focused on building equipment, without which it can not ensure a quality production, the input control of building materials, intermediate products and components, to control the technological discipline in carrying out any of construction works and quality control of implemented processes.Any controls must be conducted in accordance with the approved inspection and test plan. An essential part of this activity is consistent evidence of all results of inspections and tests and their record in the construction documents. This is mainly for planning diary that should contain information on all the circumstances of construction. In terms of quality there should be mentioned in particular:
- date of execution of works
- weather and air temperature at the time of execution of works
- properties of materials and products at the time of installation
- name of supplier of components, numbers, delivery notes and their place of installation
- production data of test specimens and test results
- records of serious controls and partial scrutineering of structures and their parts, which will be covered during further progress of the work as concrete reinforcement, insulation, seams, etc.
Interoperational control during construction should be organized so to preemptively prevent occurrence of defects, or at least prevented their transfer to other operations. Its main role is to ensure the quality of construction works by direct control of all phases of production, from the acceptance and storage of building materials through the entire process through to its delivery.
Production stage ends with final inspection and handover procedure (or acceptance), which surrenders completed construction to builder. It evaluates the overall quality of construction, on the basis of all results of the inspections and tests. The surrender and acceptance of construction prepare a record.
9.7.3 Quality control during use of the building
Stage of implementation of the project ends with acceptance. When it is checked whether the building was carried out in accordance with the approved project documentation and building permit. Now is use of a building stage, which is to demonstrate its ability to consistently fulfill the intentions of the builder. This post-production stage includes construction inspection, and its functionality in the warranty and post-warranty time. Contractor must remove the defects that occur during the guarantee in accordance with the relevant provisions of the Economic Code and the contractual obligations. Controls in post-time should bring particular knowledge and experience in those constructions, which were used developments, new materials, technologies and procedures. There may be checked for quality after longer use of the building. Evaluation of these inspections obtaines feedback to assess applied outcomes of technical developments and background material for further development to improve the quality of constructions, repair or design of deficiencies found.
Management and information system must ensure a reliable and rapid transfer of results technical inspection to the construction production in order to continue to improve the quality of all activities [5].
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9.8 Construction quality evaluationy
The quality of
construction can be evaluated
by different methods and
exact according to various
criteria. It is
very much an individual
and particularly in the area of
urbanism and architecture
is often a
question period and the
conditions in which the building
being assessed.
Evaluation of skilled professionals and builders, especially users of buildings is critical. The client evaluates compliance with specified quality requirements for project of construction and implementation. The user then evaluates the quality of construction in terms of performance and functionality, costs of operation and maintenance as well as rational in terms of user comfort indoor environment. An important criterion is the durability of building materials, durability of building structures and components.
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9.9 Training of personnel in constructions quality assurance
Training is one of the important factors leading to quality assurance of structures. It must be a continuous process, involving changes in the technological and organizational areas of production, as well as changes in the thinking of all workers and the environment of construction companies. Training must be based on the concept and goals of quality, and published guidance set out by the company, and applies to staff at all levels.
The highest decision-makers must understand the system including quality assurance methods and tools for their full participation in the system functionality. They have to understand the criteria for evaluating the effectiveness of a comprehensive quality management.
Technical staff should be encouraged to consistently increase the benefits of quality improvement. Training is be attended not only by those who are dedicated to quality issuesbut also personnel of marketing, procurement, engineering and management of production processes.
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9.10 The principles of quality management, accreditation and certification of construction companies
The application of comprehensive quality control (for details see [5]) in practice of construction companies begins with publication of the concept of quality by establishing an appropriate organizational structure and training of all staff. Other activities of the company should be governed by the following principles:
- quality of care must begin in top management,
- written instructions are one of the essential means by which management ensures its function of management and control,
- basis for management is enough timely and accurate information in order to identify and improve those systems that are capable of consistently achieving desired quality,
- quality management is a continuous, almost never-ending process.
The last principle briefly describes the basic philosophy of approach to quality. The condition of prosperity of construction companies are a constant technology innovation and improving the quality of construction processes so that they can consistently meet growing market demands.
Accreditation and followed certification of companies in the area protects the builders and users of buildings in front of poor quality of work. Construction companies improve market position and allows them to gain challenging contract and expand into foreign markets. Unification of system requirements management and quality assurance standards allow complex of ISO 9000, published in 1987. These international standards have been taken over as a national standard in more than 40 countries.
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[1] Ďurica T. and team.: Kvalita vo výstavbovom procese. Vydavatelstvo ELFA s.r.o., Košice 2000.
[2] Gašparík J.: Komplexná starostlivosť o kvalitu. ES STU Bratislava 1998.
[3] Hájek V., Jelen V., Vokálová J.: Ekonomika a management 10, část 2. Vydavatelství ČVUT Praha 1999.
[4] Vlček K.: Stavebnotechnologická príprava stavieb. JAGA a.s. Bratislava, 1998.
[5] Zapletal I., Gašparík J. and team.: Inženýrské stavby - technologie 2. Vydavateľsto STU Bratislava, 1998.
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