Sunday, October 26, 2008

Flexible Manufacturing Systems [F.M.S] : Whitepaper 03

Read the previous parts: Abstract, Part 1, Part 2

Case Studies


The Hattersley Newman Hender (H.N.H.) F.M.S.: -

This company is located at Ormskirk, U.K. and manufactures high and low pressure bodies and caps for water, gas and oil valves. These components require a total of 2750 parts for their manufacture. That is why they decided to go for the system of F.M.S. to fulfil their machining requirements in a single system. Their F.M.S. consists of primary and secondary facilities. The primary facilities include 5 universal machining centres and 2 special machining centres. The secondary facilities consist of tool setting and manual workstations.

System layout and facilities (Figure 6): -

Primary facilities: -

1.) Machining centres: - The F.M.S. contains two 5-axis horizontal ‘out-facing’ machines and five 4-axis machining centres under the host control. All the machines have a rotating pallet changer each with two pallet buffer stations. These stations transfer pallets to and from the transport system (8 Automated Guided Vehicles). The 5 universal machining centres have 2 magazines with capacity of 40 tools in each magazine. The special purpose out-facing machines (O.F.M.) each have one magazine having a capacity of 40 tools. The tool magazines can be loaded by sending instructions to the tool setting room either from the host computer or the machine’s numerical controller.

Flexible Manufacturing Systems [F.M.S]

Figure 6: - Layout of the Hattersley Newman Hender (H.N.S.) F.M.S.,

Courtesy Flexible Manufacturing, Parrish.

2.) Processing centres: - The system contains two processing centres – a wash machine and two manual workstations.

Wash machines: - it contains two conveyor belts (one for input and one for output of pallets), each with a capacity of three pallets to transfer the pallets. The wash booth has a capacity of three pallets. The pallets are washed in the booth and turned upside-down to drain out the water and then it is dried with blown air.

Manual workstations (ring fitting area): - The operator fits metal sealing rings into the valve bodies at the manual workstations. The operator receives work instructions from a computer interface with the host.

Secondary facilities: -

1.) Auxiliary stations: -

Load/unload stations: - The F.M.S. has four piece part load/unload stations. Loading and unloading is performed at these stations with the instructions received on a computer interfaced with the host.

Fixture-setting station: - At this stations the fixtures are readjusted to accommodate different piece parts.

Administration of tools: - Tools are assembled manually. The tool-setting machine checks the dimensional offsets of the tools and generates a bar code for further identification of the tool that has been set.

2.) Auxiliary facilities: -

Transport system: - The transport system consists of a controller and 8 Automated Guided Vehicles (A.G.V.). The system also contains an A.G.V. battery charging area.

Buffer stores: - The F.M.S. has 20 buffer stores in order to store the empty and loaded pallets while they are waiting they waiting to be taken to another transfer station (i.e. a load/unload station or a machine tool etc.).

Maintenance Area: - This facility cater for pallets that may be damaged or need servicing or for scrapped piece-parts.

Raw Material Stores: - These stores are located in front of the load / unload stations and are used to store the raw materials (like forged valve bodies etc). The store is served by two fork-lift-stacker cranes and motor roller conveyors. It has a capacity of 80 containers.

Fixture store: - The fixtures that are not used live in F.M.S. are stored here. It has a capacity of storing 120 fixtures. The store is served by a stacker crane and motor roller conveyors.



The Vought workshop F.M.S.

The Vought Aerospace plant located at Dallas makes two elements for the B-1 Bomber fuselage which is made up of some 2000 machined parts, 600 of which are suitable for reduction in an F.M.S. This programme is somewhat shorter than the majority of American aerospace production runs which often require 1000s of parts. This presented a problem to the company since it is not profitable to introduce specialised equipment for such short runs. So the company decided to develop an F.M.S. for this particular project.

Flexible Manufacturing Systems [F.M.S]

Figure 7: - Installation plan of the Vought workshop F.M.S

Courtesy: - Flexible Manufacturing Systems in Practice, Bonetto

Elements of the Vought F.M.S.: -

  1. Eight 4-axes Milacron 20 HC horizontal machining centre with Allen Bradley numerical control and a 90 capacity tool magazine.

  2. A washing station.

  3. 4 wire-guided vehicles.

  4. Two Carousals, each with 10 spaces.

  5. Two D.E.A. vertical measuring machines, with transverse movement and heads with two axes of rotation.

  6. A rectification centre.

  7. Swarf treating system.

The implementation of F.M.S. brought the following benefits to the company: -

  • The manufacturing process of the parts on traditional machines took about 200,000 hours. It same set of machining operations could be accomplished on the F.M.S. in about 70,000 hours. Thus it reduced the manufacturing time by 65%.

  • The total cost of installation of the F.M.S. was about 15 million dollar. The operation of the F.M.S. in a period of three years resulted in an estimated saving of 25 million dollars. This represents a return of 40% on the initial investment.

  • The whole workshop occupies an area of 2,800 square metres, which is relatively small as compared to that of the traditional workshops of the same capacity.


Factory of the future

Flexible Manufacturing Systems [F.M.S]

We have achieved complete automation in the Machining operation part of the F.M.S. and to a lesser degree in the assembly system. Automation of the various aspects of the industry has been achieved in isolation. Efforts are now being made towards integrating these isolated systems into a single entity.

This will eventually result in the formation of a completely automated super system, in which all the operations, from designing a product to packaging is fully integrated into the system. This factory would be able to function without any human interference. This will require an immense level of co-ordination between the various departments at the hardware and software levels.

The hardware used should be of a very high quality and compatibility and the software must posses an extremely high level of Artificial Intelligence (A.I.). The roles of humans in this system are that of supervision and ensuring that the system follows the direction the humans envisage. F.M.S.


Indian Context

Some companies in India have adopted F.M.S. technology for its operations. However this technology is still not widely implemented in India. For the Indian industries to sustain itself and compete in the global market it is necessary that they adopt some new generation manufacturing process like F.M.S. For this to happen the Government should also take an active part in encouraging the development of F.M.S. in India.



F.M.S.s are now being widely employed to improve productivity and quality of the product. It also improves the quality of life for the operator. The new techniques will have a major impact on economic factors. Research must be carried out in the development of the technical aspects of software and hardware to develop a better F.M.S to suit various requirements. Research must also be conducted in developing a standardisation process in certain areas, to enable its easier implementation, as present Research being done is not sufficient.

Thus F.M.S. technology has been able to fulfil the needs of the industry quite successfully. Therefore, implementation of F.M.S. will benefit both the Manufacturer and the Consumer.