In the year
of the 1960s, market competition become more intense.
Between
1960 to 1970 cost was the primary concern. Later quality became a
priority. As the market become more and more complex, speed of delivery
become something customer also needed.
A strategy
was formulated: Customizability. The companies has to adapt to the
environment on which they operate, to be more flexible in their
operations and to satisfy different market segments .
Thus the innovation
of FMS became related to the effort of gaining competitive advantage.
1. FMS is a
manufacturing technology.
2.FMS is a
philosophy. "System" is key
word. Philosophically, FMS incorporates a system view of manufacturing.
The word for manufacturer is ‘agility’.
An agile manufacturer - who is the
fastest to the market, operates with the lowest total cost and has the greatest
ability to "delight" its customers. FMS is simply one way that manufacturer
are able to achieve this agility.
Studying
FMS, we need to keep in mind what Peter Drucker said: We must become manager of
technology not merely users of technologies.
1. Flexibility concept.
Approaches are
Flexibility
means to produce reasonably priced customized products of high quality that can
be quickly delivered to customers.
Different
approaches to flexibility and their meanings are shown .
Table
1
Approach
Flexibility
meaning
Manufacturing
The capability of producing different
parts without major re-tooling
A measure of how fast the firm converts
its processes from making an old line of products to produce a new
product
The ability to change a production
schedule, to modify part rather to handle multi parts
Operational
The ability to efficiently producing highly customized and unique products
Customer
The ability to exploit various dimension
of speed of deliveries
Strategic
The ability of a firm to offer a wide
variety of products to its clients
Capacity
The ability to rapidly increase or
decrease production levels or to shift capacity quickly from one product
to another
Thus, what
is flexibility in manufacturing?
While
variations abound in what specifically constitutes flexibility, there is a
common concept about the core elements. Three levels of manufacturing flexibility.
(a) Basic flexibilities
Machine flexibility – is the ease with which a
machine can process various operations
Material handling flexibility – is a measure of the ease
with which different part types can be transporer and properly positioned
at the various machine tools in a system
Operation flexibilities – is a measure of the ease
with which alternative operation sequence could be used for processing a part type
(b) System flexibilities
Volume flexibility –is a measure of a system’s capability to be
operated profitably at different volumes of the existing part types
Expansion flexibility – is the ability to build a
system and expand it incrementally
Routing flexibility –is a measure of the alternative paths that a
part could effectively follow through a system for a given process plan
Process flexibility –is a measure of the volume of the set of
part types that a system can produce without incurring any setup
Product flexibility – is the volume of the set of
part types that can be manufactured in a system with minor setup
(c) Aggregate flexibilities
Program flexibility – is the ability of a system
to run reasonable long periods
without external intervention
Production flexibility – is the volume of the set of
part types that a system can produce without dominent investment in
capital equipment
Market flexibility – is the ability of system to efficiently adapt to changing
market conditions
2. Seeking benefits on flexibility
Today’s
manufacturing strategies is to seek benefits from flexibilities. This is only
feasibility when a production system is under complete control of FMS
technology. Process- Product Matrix you may realize for an industry it is possible to access for
high flexibility by making innovative technical and organizational efforts.
Example :Volvo’s process structure that makes cars on movable pallets, rather
than an assembly line. The process gains in flexibility. The Volvo system has
more flexibility because it uses multi-skill operators who are not paced by a
mechanical line.
We may
search for benefits from flexibility on moving to the job shop floor structures.
Actually,
the need is for flexible processes to permit rapid low cost switching
from one product line to another. This is possible with flexible worker
whose multiple skill will develop the ability to switch easily from one kind of
task to another.
3. FMS- an example of technology and an
alternative layout
FMS was proposed in England -1960s under the
name ‘System 24’, a flexible machine system
that will operate without human operators 24 hours a day at computer control. Beginning
-the emphasis was on automation rather than the ‘reorganization of
workflow’.
Past FMSs were large and very complex, consisting
of dozens of Computer Numerical Controlled machines (CNC) and sophisticate
material handling systems. They were highly automated, very expensive and
controlled by incredibly complex software. There were only a limited number of
industries that could afford investing in a traditional FMS as described above.
4. Advantages and disadvantages of
FMSs implementation
Advantages
Faster, lower - cost changes from one part to another would
improve capital utilization
Lower direct labour cost, due to the
reduction in number of workers
Reducing inventory, due to the planning
and programming precision
Consistent and better quality, due to the
automated control
Disadvantages
Limited ability to adapt to changes in
product or product mix .Example machines are of limited capacity and the tooling
necessary for products- even of the similar family, is not always feasible
in a given FMS
Substantial pre planning activity
Expensive & costing millions of
dollars
Technical problems of exact component
positioning and precise timing necessary to process a component
WHEN SITUATION OF KICK ARISE BOP IS DESIGNED TO ACTIVATE MANUALLY,WHICH ISOLATE WELL BORE FROM SURFACE & CLOSE THE WELL.IT COMES IN COMBINATION OF VALVES.THE BOP IS PLACED AT THE TOP OF WELL HEAD.THE BOP COLLECTIVELY KNOWN AS BOP STACK.IT IS A MODERN TECHNOLOGY USED TO CONTROL THE WELL BORE PRESSURE TO KEEP OIL AND GAS ESCAPING INTO THE ENVIRONMENT. KICK: - ENTERING OF FORMATION FLUID INTO WELL BORE BLOW OUT : - UNCONTROLLED FLOW OF FORMATION FLUID INTO WELL BORE
BOP CAN BE CLASSIFIED MAINLY INTO TWO TYPES:-
ANNULAR BOP
RAM TYPE BOP
ANNULAR BOP
• IT IS PLACED @ TOP OF BOP STACK.
• IT HAS A DONAR SHAPE PACKING RUBBER ELASTOMER TO HOLD THE PIPE.
• IT HAS 2 MOVING PART A PISTON & A PACKING UNIT.
• PISTON PUSHES THE PACKING UNIT TO CLOSE THE WELL.
• IT WILL NOT PROVIDE GOOD SEAL, SO NOT APPLICABLE FOR HIGH PRESSURE.
RAM TYPE BOP
According to the shape of die it can be classified into:-
a) PIPE RAM BOP
b) BLIND RAM BOP
c) VARIABLE RAM BOP
d) SHEAR RAM BOP PIPE RAM BOP
• IT HAS A CIRCULAR CUT OUT.
• CIRCULAR CUT OUT IS TO HOLD THE DRILL PIPE & SEAL THE WELL.
• IT IS DESIGNED TO FIT PARTICULAR SIZE OF DRILL PIPE
VARIABLE RAM BOP
• IT HAS VARIABLE CIRCULAR CUT OUTS
• IT IS MENT TO CLOSE THE DRILL PIPE HAVING VARYING DIMENSION.
BLIND RAM BOP
• USED TO CLOSE THE WELL WHEN THERE IS NO STRINGS IN THE WELL.
• IT CONSIST OF FLAT PLATES THAT WILL SEAL THE WELL
SHEAR RAM BOP
• IT CONSISTS OF BLADES WHICH IS CAPABLE OF SHEARING THE DP.
• WHEN THERE IS STRING IN THE WELL, THIS TYPE RAM SHEARS STRING & CLOSE THE WELL.
FUNCTIONING OF BOP
If there is an indication of fluid entering the wellbore from sub surface formation while in drilling time or tripping time, As a first step BOP can be activate manually, that isolate the wellbore from surface and close the well. it is designed to activate automatically in case of decrease or increase in pressure in the well bore.
Capillarity is a phenomenon of riseor fall of liquid surface relative to the adjacent general level of liquid. This phenomenon is due to combined effect of cohesion and adhesion of liquid particle The rise of liquid level is known as capillary rise where as the fall of liquid surface is known as capillary depression .It is expressed in terms of cm or mm of liquid.
The magnitude of capillary depend upon Diameter of tube ,d Specific weight of liquid ,w Surface tension of liquid,∞