Unit 7 (2017)Apunte Inglés
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Unit 7: Productive process and facility layout design
It is the determination of the best disposition of the different elements of the productive
process so that the fixed goals are achieved adequately and efficiently.
Main objectives - Reduction of congestion.
Suppression of areas that are unnecessarily occupied.
Reduction of maintenance (displacement of materials and/or products that do not produce any transformation).
Reduction of the material inside the productive process.
Reduction of risks that affect the material or its quality.
Reduction of delays and the production timings Increment of workers’ security.
Optimization of labour, machinery and services.
Improvement of staff satisfaction.
Reduction of indirect administrative work.
Improvement of supervision and control.
Improvement on the adjustments in changing conditions Factors to be considered - Flow of materials Equipment and its dimensions.
Secondary services (wardrobe for tooling, spare parts, meeting rooms, toilets,… Building limitations (columns, heating /air conditioning outputs,…) Materials flow Types of layout A. According to industry sector: a. Mono-linear industries. Production follows a unique circuit, always the same.
The steps of this circuit are followed by all the materials (flour industries, cement industries,…).
b. Synthetic or convergent industries. Raw material and intermediate products arrive from different places and join in the final production line (automotive industries, bottling plant,…) c. Analytical or divergent industries. Raw material is processed and diverges in several final products (Chemical companies).
d. Convergent-divergent industries. Several number of raw materials converge in an intermediate product that afterwards diverges in several final products (Chocolate companies) B. According to production organization: a. Fixed position layout. Applies to large product units which are either difficult to move at early stages such as ships, aircraft, or alternatively, they cannot move (buildings, bridges,…). The product is in a fixed position. Materials, machines and subcontractors move to and from the product.
Advantages: Low handling of the mounting unit.
Disadvantages: Compulsory to move materials, machinery and subcontractors to where production is performed. Sometimes, space will be required.
b. Fluid flow c. Assembly line layout. The work units are located one after the other, following the operations order.
Advantages: Reduction of orders in progress, reduction of delivery terms and easy planning.
Disadvantages: Big lots are necessary, work balancing is more difficult, rigid planning.
d. Functional layout. The work centres are joined by group of activity (hospital, recovery room, kitchen) Advantages: Flexibility to changes in product and/or quantities, lower investments than previous configuration. It’s easier to maintain the system performance in front of possible problems or breakdowns. Task diversity improves satisfaction of operators.
Disadvantages: Expensive maintenance due to longer movements. Planning and control is more difficult. High volume of orders in progress. Longer delivery terms (waiting times between tasks). Higher unitary cost. Low productivity (each operation is different. It requires different organization and a different training).
Line layout: - Mixtures the benefits of unitary work or small lots with the advantages of the assembly line.
Work centres are distributed in chains. Each one is dedicated to the execution of several tasks.
It requires a previous classification of the pieces in families.
Inside one family, operations are carried out in the same sequence.
Some operations can be skipped for certain products.
Tooling must be changed rapidly.
Advantages: Low orders in progress (output of a work centre goes immediately to the next), minimum internal transport because work centres are close. Planning and control is easy, Operators are NOT specialised and they are easily trained and fired.
Disadvantages: Inflexibility to product design changes. System prone to breakdowns, high investment is required. Repetitive work affects satisfaction and efficiency . The rhythm to balance the line is determined by the lowest work centre.
Distribution by products and by services Distribution according to production organization A. Hybrid distribution: Cellular distribution. Distribution based on the product (efficient) and distribution based on the process (flexibility). Personnel and machinery are grouped when normally they will be in different sections of the process. A small team is trained to produce a unique product or set of related products.
Surface calculation Total surface of each element should be calculate as follows: 𝑆𝑇 = 𝑆𝑆 + 𝑆𝐺 + 𝑆𝐸 - - SS : Static surface, that corresponds to furniture, machinery or facilities.
SG : Gravitational surface, is the surface that it’s used around the workstation by the operator and by the material accumulated during the operations in progress. This surface is calculated for each element: SG = SS * N , where N is the number of sides that must be accessible when the machine is working.
SE : Evolution surface, surface that must be reserved between the workstations to ease the personnel displacements and maintenances (corridors). This surface is calculated according to the formula: SE = (SS + SG ) * K, where K is a coefficient that can vary from 0,05 to 3.
Note: The surface dedicated to stocks does not consider gravitational surface; only static surface and evolution surface are taken into account Fictitious range The objective of this method is to find the adequate location of the work stations so that the configuration can adapt to all production flows. Sometimes, it is necessary to duplicate work stations.
Layout in service industries It has the following characteristics: - More direct contact with customers.
Search of satisfaction and wellbeing of customers.
Attractive appearance of the areas in contact with customers.
There is no prediction of work load.
There is no programming of activities.
Office layout The material that is transferred among departments and work stations is nearly exclusively information. This is done by: - Individual conversations Telephone conversations and/or Internet calls.
- Postal service and other documents.
Emails Meetings and discussion groups Videoconferences.
The distribution is determined by workers and documents movement. It depends on the total area, its shape, the developed process and the relations between workers.
Shops distribution The objective is to maximise the net profit by square meters of shelves. The sales square meters and warehouse must be optimised.
- Daily necessary products should be placed in the periphery Products of impulsive purchase must be placed in prominent places.
Removal of corridors that allow to go from one shelf to another without covering all of them.
Special discounts and offers should be distributed at both ends of shelves.
Usage of the end of shelves as exhibitors of products.
The shop image is determined by selecting the first accessible shelf properly.
If we accept that sales vary according to the exhibition of products to clients, the objective of the distribution will be to exhibit as many products as possible in the available space.
Warehouse distribution The objective is to find the optimal ratio between the handling cost of materials and the storage space. Aspects to be considered: - The usage of cubic meters.
Warehouse equipment and methodology.
Protection of materials.
Location of materials.
Nowadays computers ease the problem of articles location in a warehouse. Articles can be placed in a disperse way so that the first free space is used and afterwards articles are searched by computers. Besides, collection routes can be optimised.