TOTAL QUALITY MANAGEMENT (Part -II)
QA / QC Difference
A QC Engineer is the one who finds defects in a product whereas
A QA Engineer is the one who finds preventive actions to eliminate the defects in the product.
QC QA
Product Oriented Process oriented
Reactive Pro-active
Line Function Staff Function
Find the defects Prevent the defects
e.g.
QC QA
Walkthrough Quality Audit
Testing Defining Process
Inspection Selection of tools
Checkpoint Review Trainings
WHY QUALITY ASSURANCE?
The need for a sustainable built structure calls for quality control throughout the entire process of its construction. QA pays attention to the following aspects:
1. Quality control in pre-planning
2. Quality control in site organization, construction process and supervision
3. Quality control in health and safety of personnel
PLANNING AND SITE ORGANIZATION
Careful forethought and planning are required for sound site organization. Consideration must be given to the efficient use of available space at the site during building operations in order to ensure that all building activities move smoothly with minimal interference or delay. The proper choice of suppliers and subcontractors plays an important part in achieving desired quality and efficiency.
THE CONSTRUCTION PROCESS AND SUPERVISION
Reliable standards must be maintained throughout the whole construction process in order to ensure that the built work is durable, is functionally sound and aesthetically satisfying.
Simple time-tested methods that have proved effective in ensuring quality can be employed to make sure that problems do not develop later, which can be expensive and difficult to rectify.
Close supervision of craftsmen and workers employed by the main contractor on the site is essential to make certain that all the elements that make up the building conform to acceptable standards of quality. The work of sub contractors too requires planning and supervision to ensure quality is maintained in all aspects of construction, including services.
HEALTH AND SAFETY
Health and safety are factors that must be pursued with as much vigour as other management objectives. Ensuring the well-being and safety of all workers or visitors at construction sites will improve performance; minimize accidents and illness which in turn will reduce disruption of work as well as consequent expenses.
The following checklist is prepared so that building contractors and supervisors can make sure that essential steps are taken to ensure maintenance of quality control throughout the building process.
Note: In checking out the Yes/No response to each question, it is important that if the answer is No, follow-up corrective action is needed.
PRE-PLANNING
PRELIMINARY ASSESSMENT OF PROJECT
Have
you?
.
Carefully studied the architectural and structural drawings
Yes
__ No __
. Carefully studied the terms of the contract, the Specifications and Bill of Quantities BOQ* (* i.e. list of materials with corresponding quantities required for work items)
Yes
__ No __
. Noted any discrepancies or items that are not clear to you in the architectural and structural drawings, Specifications and BOQ
Yes
__ No __
.
Requested the clarifications on items unclear to you in drawings and other documentation
from the architect and engineer and client
Yes
__ No __
. Made sure that information provided in the drawings and other documentation is adequate, also that the terms of the contract are acceptable for proceeding with preparatory work for construction at the proposed site
Yes __ No __
. Prepared a Bar Chart that lists the sequence of building activities with corresponding time periods for completing each activity, taking into account holidays, inclement weather and other factors that are likely to cause delays
Yes __ No __
DETERMINE REQUIREMENTS – PLANT/EQUIPMENT, MATERIALS, AND PERSONNEL
To
determine plant/equipment and materials requirements:
Have
you?
.
Studied the plans and specifications in relation to the
phases
of construction shown in the Bar Chart
Yes
__ No __
. Double checked the accuracy of the Bill of Quantities
Yes
__ No __
. Listed the materials required at each successive stage of construction (See specimen materials schedule – annexed)
Yes
__ No __
To determine personnel requirements:
Have you?
.
Drawn up a schedule of personnel required for carrying out the project to
completion (See specimen schedule of personnel – annexed)
Yes
__ No __
DETERMINE TIME FRAME FOR COMPLETING PROJECT
Have
you?
.
Checked the Bar Chart ‘s time periods for completing each activity in sequence,
taking into account holidays, inclement weather and other common factors that
cause delays and determined the feasibility of completing work on schedule
Yes
__ No __
Quality and conformity to the
specifications should be the primary consideration and not the cheapest price
when choosing suppliers and materials.
Whenever and whatever the contractor
aims to purchase, he should aim to buy:
the right quality - at the right time - the right quantity - from the right source - at the right price
Have
you?
.
Made sure that an experienced and knowledgeable purchasing officer has
personally visited the premises of the suppliers and has established the
reliability of each supplier and the quantity of the materials that are to be purchased
from them
Yes
__ No __
.
Made sure that the supplier has reliable means of transporting materials to the
site at the required time/s
Yes
__ No __
.
Compared the rates given by at least two other reliable suppliers to determine whether
the prices agreed upon are compatible and not excessive
CHOOSING SUBCONTRACTORS
Look
for real value and not the cheapest cost when choosing subcontractors, the same
as is needed with choosing suppliers. Also, it is important that certain installations,
such as electrical and plumbing, require personnel who are qualified and
experienced in their respective fields of activity if quality in installation
is to be assured.
In
choosing suitable subcontractors
Have
you?
.
Investigated their financial standing and satisfied yourself that their financial
status is satisfactory
Yes
__ No __
.
Checked on whether the subcontractors and their staff of tradesmen are
sufficiently experienced and skilled to carry out their respective tasks
Yes __ No __
.
Checked on whom they worked for before and whether such persons can be
approached for reference
Yes
__ No __
.
Found out who in their labour force are permanently employed and who are
casually recruited
Yes
__ No __
.
Found out if the contractor or tradesmen have their own tools and specialist
equipment
Yes __ No __
.
Found out if the contractor or tradesmen have their own transport that is
dependable
Yes
__ No __
.
Established whether the contractor is reasonably free from other current
commitments in order to give adequate attention to the proposed work
Yes
__ No __
.
Established if the contractor is able to complete the work assigned on time
Yes __ No __
.
Established clearly the terms and conditions of payment, including the
contractor’s commitment to correct substandard work (due to non conformity to given
specifications/ drawings and prevailing standards) at his own cost
Yes
__ No __
OVERSIGHT OF SUBCONTRACTORS
In
order to ensure that each subcontractor clearly understands his rights and
responsibilities in carrying out the work assigned
Have
you?
.
Given a clear description of the work to be done, including the work of making
good the work of previous trades* (*construction work items done by others
earlier)
Yes
__ No __
Yes __ No __
Yes
__ No __
Yes
__ No __
Yes
__ No __
Yes
__ No __
.
Established the time limits for commencing and completing the elements in the
subcontract work, based on the general programme, and commitment to complete
work on schedule, as well as the penalty to be imposed due to delay in
completion
Yes __ No __
. Arranged for supervisors by the client or client’s representative
Yes
__ No __
.Made sure that worker safety and welfare arrangements are satisfactory
Yes
__ No __
Yes
__ No __
Have
you?
.
Given a clear description of the work to be done, including the work of making
good the work of previous trades*(*construction work items done by others
earlier) that have been affected by the work of the workmen
Yes
__ No __
.
Made clear the terms and conditions of engagement
Yes
__ No __
Yes
__ No __
Have
you?
.
Chosen and appointed an experienced and competent supervisor to oversee the
work done by personnel who are to carry out all types of building activity on
the site
Yes __ No __
Yes
__ No __
Yes
__ No __
Yes
__ No __
HEALTH AND SAFETY AT THE WORK SITE
The
physical well being and safety of workers on site as well as safety of visitors
to the site should be of primary concern to the contractor and implementation
of a project. An accident prevention programme should be established to
minimize the number of accidents that can happen on a building site. All workers
should be briefed on safety standards and measures to be taken to handle
accidents. ‘Good housekeeping’ on a construction site is very important if accidents
are to be avoided. Good housekeeping on a construction site includes the
following:
1.
Keeping the site tidy
2.
Quickly clearing away debris that can be hazardous to persons moving around the
site
3.
Removing nails from used timbers
4.
Making sure that nails, broken glass and other harmful objects are not left
lying around
5.
Making sure that each worker is personally responsible to clean-up as well as
make good whenever needed after an item of work is completed.
6.
Making sure that live power lines with unprotected joints and exposed wires are
not allowed to be used or left exposed in a way that may cause harm to persons
7.
Making sure that materials are stacked in a manner that would not cause harm to
persons
8.
Making sure that any live flames are not left untended if they are used at all
for a purpose Practical Action
9.Making
sure that pits or excavations are clearly identified and protected so as not to
cause injury to people by using marking tape, danger signs or red flags as
appropriate
10.
Making sure that plastic or polythene sheets are not used as temporary floor covering
in locations especially where ladders are used because such coverings are too slippery
and dangerous
11.
Making sure edges of covering material on the floor are well tucked in so as
not to cause persons to trip
12.
Making sure that floor surfaces on which water has spilled are quickly mopped
and made sufficiently dry to prevent injury due to persons slipping.
13.
Making sure that animals and children are kept out of working areas and all materials
and tools and paint are kept out of their reach
14.
Making sure that workers at the building site tie back long hair or tuck their
hair into a hat or helmet
15.
Making sure when painting to keep the room well ventilated and not allow eating
or smoking while painting or using equipment
16.
Making sure that the right tools and equipment are used for the job at hand;
never just improvising with whatever is on hand that is not suited to the work
17.
Making sure that all workers who may have paint splashed on their skin, use
only proprietary cleaners to remove it, never solvents or other chemicals
18.
Making sure that rubbish is disposed of carefully, never throwing chemicals
down drains, but follow pack instructions
19.
Making sure those flammable items – gloss paint, undercoat, primer and white spirit
– are stored well away from any source of ignition
20.
Making sure that suitable measures are taken to ensure that the base of any
ladder in use does not slip
21.
Making sure that raised working platforms are stable and of adequate size and
can hold the weight of persons and materials on them.
Other protective and preventive measures are:
.
Make sure that protective gear and equipment are used – such as gloves, eye
shields for welders, safety helmets, safety belts, face masks etc.
.
Make sure that a well equipped first aid kit is made available on site and
readily accessible to all persons on the site. Needed items for cuts, bruises,
burns and other injuries that require first aid treatment should always be stocked
in the kit and quickly replenished when used.
.
Ensure that a stretcher is always on hand at the site and properly used when it
is not advisable to lift and carry injured people without a stretcher. When the
injured person is suspected to have severe fractures or broken bones stretchers
have to be used.
.
Ensure that all workers and persons who visit the site are not permitted to
walk barefoot, because of the danger of being injured and the wound caused by
the injury being infected.
Accidents
Accidents
can and do happen and on such occasions it is important that these be handled
properly and promptly because the first hour is critical. Special procedures
should be outlined and explained to all who work on site. When accidents do
happen, the following action should be taken:
1.
Use items in the first aid kit that is on site as appropriate to the injury
2.
Arrange for immediate transport of the injured person/s for needed medical
attention
3.
Site supervisor should fill out an accident report for each injured person –
the form should provide for inclusion of the name of the injured person, the
nature of the injury, the cause of the injury/accident, and what was done when
the accident occurred.
4.
The contractor must take follow-up action on the report, which includes arranging
for the patient to be visited and next of kin informed speedily, and conducting
an investigation into the accident that may warrant disciplinary action as well
taking steps to prevent recurrence of the accident on site. It is important that
the addresses of all workers on site are readily available as well as the name/s
of next of kin and their addresses and telephone numbers.
Have
you?
.
Taken all the protective/preventive measures outlined in the Good Housekeeping
list above
Yes
__ No __
. Made sure that workers on site have the necessary protective gear to ensure their health and safety
Yes
__ No __
. Arranged to brief all workers on the site regarding the importance of safety and the need for good housekeeping on the site
Yes
__ No __
.
Clearly explained to all workers on the site the procedures that must be
followed when accidents do happen
Yes
__ No __
MANUAL HANDLING AND LIFTING OF MATERIAL AND EQUIPMENT
Despite
the availability of numerous mechanical aids for handling and lifting materials
and equipment at construction sites, many operations call for manual handling
and lifting. Records indicate that at least one third of all industrial accidents
occur when workmen are lifting, lowering, pushing or pulling while handling material
or equipment. A large number of these accidents are due to workmen using wrong
methods or attempting to lift or carry weights beyond their physical capacity.
They result in strained back muscles, or slipped or ruptured spinal discs,
hernia and other painful injuries. Most of these injuries can be avoided by the
Practical Action.
SITE ORGANIZATION
PREPARATION OF THE SITE
Have
you?
.
Cleared the surface of grass and other vegetable matter as well as roofs of
all, felled and fallen trees, plants etc. that come within the area of the
proposed building/s.
Yes
__ No __
. Removed topsoil at the site and stockpiled (in a suitable place) the removed topsoil for later reuse in the garden surrounding the proposed building
Yes
__ No __
. Ensured that the area for the proposed building is properly drained of surface water so as to prevent the collection of water within or very near the proposed building area during and after construction is completed
Yes
__ No __
LOCATING OF SERVICES ON SITE
Have
you located on site – the following?
.
Area for storage of cement, aggregate, sand, timber, steel, bricks, stones
Yes
__ No __
.
Concrete mixer and concrete mixing platform
Yes
__ No __
.
Lock-up store for equipment and tools with necessary racks, bins etc.
Yes
__ No __
.
Temporary toilet/s for workers (if no off site toilet is available)
Yes
__ No __
.
A place where a First Aid kit can be accessible to all workers on site
Yes
__ No __
.
A site office with racks for documents and basic furniture
Yes
__ No __
SETTING
OUT THE BUILDING
Have
You?
Checked squareness of square or rectangular buildings
by
using the 3, 4, 5 method.
.
Checked the site levels in relation to the access road measurement of 4 feet
(or 4 equal units of measure) levels and fixed the finished ground level at an
elevation starting from the end of the axis 1 wall. The point of above the
crown of the access road and at a height that coincidence indicates the line of
the perpendicular will prevent entry of surface water from the road into the adjacent
wall.
Yes
__ No __
.
Pegged out the frontage of the building in relation to the building line
Yes
__ No __
EXCAVATION FOR FOUNDATIONS
Have
you?
.
Made sure that excavated soil is not stacked too close to excavations, to prevent sides of trenches from collapsing
and excavated soil reentering the trench.
Yes
__ No __
.
Used support work if necessary (in sandy or unstable soil) where side walls of
trenches show evidence of collapsing readily
Yes __ No __
CONCRETE WORK AND MASONRY WORK
CONCRETE
& REINFORCED CONCRETE WORK
.
Made sure that the reinforcement steel bars are properly hooked at the ends to
facilitate anchoring
Yes
__ No __
.
Made sure that reinforcements in intersecting columns and beams are carried
straight through junctions
Yes
__ No __
. Made sure that when laying reinforcement steel in slabs – the main steel bars are laid under the distribution steel bars
Yes
__ No __
. Made sure that sizes and spacing of all reinforcement steel and stirrups are placed strictly in conformity with the structural drawings
Yes
__ No __
. Made sure that the structural
engineer has checked and approved the steel reinforcements laid for each of the
following stages before concrete is poured:
Column
footings and columns
Yes
__ No __
RCC
foundations to walls
Yes
__ No __
Plinth
beams
Yes
__ No __
Ring beams and other beams in superstructure
Yes
__ No __
Floor slabs
Yes
__ No __
Flat roof slabs
Yes
__ No __
Other
RCC work not listed above
Yes
__ No __
MASONRY WORK
.
Made sure that the masons, working stone and brick work, have followed the
guidelines listed in the above-named
Yes
__ No __
. Made sure that plasterers and tile layers have properly followed the guidelines listed in the above-named
Quality
Assurance Checklists
Yes
__ No __
.Made sure that intersecting masonry walls bond truly with each other by proper placement of cross walls
Yes
__ No __
. Made sure that openings for doors and windows have adequate allowance of masonry space on either side of the door/window for its framing (especially the head frame) to be securely fixed
Yes
__ No __
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