Download - Small Shipyard

Design of a Small Shipyard Facility Layout Optimised for Production and Repair

Hamid CHABANE Commandement des Forces Navales

Introduction Productivity and competitiveness in shipbuilding industry depend to a great extent on the economy of scale. Achieving economic sustainability becomes a top priority goal. This issue is even more critical for small shipyards intended to produce ships of between 1000 and 5000 DWT, for the related market segment is characterised by an intense and tough competition. In addition production processes are rather different than repair and maintenance works. Their needs are quite different and often irreconcilable, and whilst the former may not systematically yield benefits despite being technologically efficient, the latter can still prove highly competitive and profitable. A possible solution could reside in a combination between a suitable product mix made of high added value ships and appropriate repair activities. Then a question arises whether it is possible or not to combine the two activities within a single shipyard in order to address its performances in periods of fluctuating demand? Visibly this would only be realized through a balanced share of some facilities and resources. The viability of such a solution will obviously depend on the ability of the shipyard to share some resources and conjugate jobs and tasks from the two separate departments by identifying and taking advantage of their similarities. Therefore the layout of the concerned facilities ought to be methodically designed and implemented and should not develop according to peculiar circumstances. This study aims to investigate how could those similarities and interdependencies be exploited to address the shipyard performances in periods of fluctuating demand? The study will be based on a thorough and extensive analysis of the work processes that are implemented by the two industrial activities taking into consideration the practices currently applied by shipyards of similar features, and emphasizing work organisations that are based on Group Technology concepts. The layout design will then be carried out and optimised by means of Muthers systematic procedure in three steps contemplating respectively:

a production layout, a repair layout, a mixed layout combining both production and repair activities,

the latter being developed upon a combination of the results relating to the first two cases. Work Organization 2.1 Facility Layout Definition FACILITY LAYOUT is defined as the arrangement of facilities aimed to achieve the operational objectives of an enterprise at minimum costs and with maximum efficiency. A poor layout can reveal highly detrimental to productivity and consequently to profitability. Symptoms that are peculiar to a poor plant arrangement can be summarised into: - great travel distances in the flow of materials - bottlenecks in the shipment of resources - excessive handling of materials - poor information circulation

Symposium International : Qualit et Maintenance au Service de lEntreprise QUALIMA01 - Tlemcen 2004

- inefficient communication system - low rate of machine and labour utilisation to name but some of them. The causes that may lie behind such deficiencies may reside in: - insufficient infrastructures - inefficient location arrangement of the various departments - poor handling equipment - inadequate fabrication processes and technology - inefficient planning system

Therefore it is primordial to plan a facility layout rather than let it develop according to the prevailing circumstances. It consists of a procedure that thoroughly contemplates all the production processes of the enterprise starting from the material procurement and taking into account the actual prevailing environment. It is expected that such approach will carry some incontestable benefits, viz: - optimal utilisation of space and equipment - more efficient flow of materials - efficient materials handling - improved production process - better planning system - work organisation flexibility 2.2 Review of Group Technology Principles Group technology may be defined as the logical arrangement and sequence of all facets of company operation in order to bring the benefits of mass production to high variety, mixed quantity production, (Storch et al., 1988). The shipbuilding industry is very peculiar. It produces to order and therefore retains some basic stages which could be modernised and automated only for very high throughputs. During the 1960s the tendency was that of large investments and profits resulted from high production rates. The increasing complexity of the shipbuilding industry coupled to the tough competition faced by most of the shipyards drew the sector from a fundamentally craft oriented industry towards the adoption of new production processes based on cost reduction strategy (Garcia and Torroja, 1994) which culminated in the late 1970s with the wide spread implementation of Group Technology concepts. From the 1980s onwards, the concept of Group Technology was developed and increasingly implemented in shipyards with undeniable advantages and benefits as illustrated in appendix 1.

2.2.1 - Work Organisation

The new trend was Engineering for production, that is the necessity to adapt the engineering work to the requirements of an efficient production system relied on an accurate and organised information flow (Garcia and Torroja, 1994). Storch achieved a methodical investigation and study of the work organisation according to Group Technology concepts. He considered and examined the cases of several US and Japanese shipyards that pioneered the experience. (see figure 1) (Storch et al., 1988). The implementation of Group Technology in the design and production process directly influences the work organisation as it requires an adequate planning system which extensively uses overlapping and parallelism, particularly between the design, engineering and construction processes, in the endeavour to reduce costs and maximise the utilization of investments. Thus the implementation of Group Technology radically modified the circulation of elements (information, materials, and personnel) between the main components of a shipyard. Besides, the complexity of the activity organisation in a shipyard which implements Group Technology requires a reliable and efficient Quality Control System in order to reduce rework. Assembling various blocks often produced in separate locations with different production processes is tributary of a high level of accuracy and coordination.


Figure 1 - Effect of Group Technology on the activity pace of a shipyard (Storch et al.,

1988) 2.2.2 Product Work Breakdown Structure (PWBS)

Storch subdivided the building process into three categories: hull construction, outfitting, and painting, with zone predominance in planning and managing as shown in figure 2. The final product results from the integration of different but interrelated processes:

- The Hull Block Construction Method (HBCM) - The Zone Outfitting Method (ZOFM) - The Zone Painting Method (ZPTM)

The Family Manufacturing (FM, e.g.: Pipe shop, Machine shop, Electrical shop) Basically, the ship is broken down into elementary products that can be grouped into families of units, best known as interim products, achievable through consistent and repeatable processes. The processes are analysed in order to specify the various operations and equipment that are involved. The analyses contemplate the products features, the make-vs.-buy alternatives, and the possible production methods. Various breakdown structures may be considered depending on the problems that are dealt with (Bruce and Garrard, 1999).

Figure 2 - Integration of different work breakdown structures (Storch et al., 1988)

2.2.3 Outfitting Operations

With the implementation of Group Technology, the outfitting operations shifted from the former accomplishment by system and sub-system towards the preoutfitting on the units prior to their erection. Successively, the preoutfitting evolved into the zone outfitting (ZOFM) which disconnects the operations from the hull construction advancement (Chirillo, 1979). The


products are subdivided into sub-groups independently of the final location on the ship. The logic is the same as that of HBCM. Indeed, both ZOFM and HBCM must be planned simultaneously, i.e. a ZOFM can only be applied if an HBCM is implemented.

2.3 Evolution of Shipyard Layouts Shipyards layouts dramatically evolved from a 1st generation pattern in the pre-WWII to a 4th generation one in the late 1980s (figure 3), and even to a 6th generation during the last decade (Bruce and Garrard, 1999). This evolution resulted from a massive implementation of Group Technology production processes (Storch et al., 1988). The experience of the 1970s showed that investments in facilities for mainly upgrading the mechanisation tools and the lifting capacities were detrimental to flexibility and most of the concerned shipyards collapsed when the 1970s crisis happened. On the other hand, those which focused more on the integration of Group Technology principles with the existing technology improved their management and pioneered the 4th generation shipyards which addressed the work organisation and the management system rather than the facilities development (Bruce and Garrard, 1999). Particularly the shift from the 3rd generation to the 4th generation shipyard was accentuated by the outfitting approach. In the former, pre-outfitting was considered as a separate process, while in the latter, the layout is based on the integration of HBCM, ZOFM and ZPTM processes, leading to the subsequently adopted U-shaped arrangement of shops around the building area better known as compact shipyards (figures 3).

Figure 3 - 4th generation shipyard layout (Storch et al., 1988)


Methodology 3.1 Review of the Systematic Layout Planning Design Method Until the advent of systematic approaches in the 1970s, layout planning was perceived as an abstract achievement, and most of the approaches which were undertaken resulted from a combination of experience, customs and established procedures. Richard Muther is the first designer who ever formalised in a well structured pattern the layout planning design process (Muther, 1973). It is quite evident that such an approach helps avoiding obvious insignificant mistakes that might yield unwanted consequences over a long term. Layouts are designed to satisfy existing demands in defined contexts. The proficiency in designing good layouts is ineffective if the demand is ill identified and defined. There could be no good solution to a false problem, for too simplistic assumptions would represent an unrealistic situation leading to a useless answer (Apple, 1991). Two questions are central: What is to be produced? How much is to be produced? A great attention must be paid to the initial data which must be reliable and accurately defined and estimated. The basic data that are required as input to the procedure amount to five, viz.: the Product P, the Quantity Q, the Routing or Process R, the Supporting Services S, and the Time T (figure 4) (Muther, 1973).

Figure 4 Systematic Layout Procedure pattern according to Muther (Muther, 1973) In the early stage of a layout design, the industrial processes are broken down into elementary actions and tasks, analysing for each unit the operations to be performed along with the subsequent required equipment. This is the stage where some fundamental decisions are taken: which parts will be produced on the location, which parts will be subcontracted or purchased, which services will be relocated, and where will it occur, etc... The optimisation technique is basically graphical. On the other hand, sophisticated quantitative methods are available but they necessitate accurate and reliable data, which is


often unlikely especially in the case of a new design. Yet, it must be pointed that a conventional graphical procedure can sometimes prove more valuable and productive for a simple layout, while some probabilistic methods can reveal more appropriate in the case of irregular service performance due to a random demand.

3.2 Materials Flows All these prerequisites yield the flows of elements, were they comprised of personnel, materials or parts. This stage of the planning is capital since it underpins the efficiency of the enterprise (Apple, 1991). A great emphasis is put on the evaluation of the flow of materials, since an imperfectly appreciated flow of materials would likely lead to an unsuitable solution (Muther, 1973). Therefore it is of the utmost importance for the flow pattern to be planned and not left to develop in a haphazard way.

3.3 Adopted Approach The approach that is adopted for the case study consists of three main parts that are developed in sequence. The first part concerns the layout design of a facility intended for production. Firstly some basic assumptions will be made regarding the product mix and related volumes of production of the shipyard in project, the work organisation, the outsourcing strategy, and subsequently the main facilities that will be retained on site. The space requirements will be determined either using standard data, or based on statistics relating to shipyards of similar sizes and features. In the same way the second part deals with a facility dedicated to ship repair. The main assumptions regard the repair workload that will relate to that of a similar shipyard object of an MSc Thesis developed at the Department of Marine Technology of the University of Newcastle upon Tyne (GB) in 1989 (Zenasni, 1989). A thorough analysis will be carried out about the docking and berthing capacities required by such a workload, for these facilities comprise the backbone of a ship repair yard. Finally the third part will contemplate a mixed facility designed to handle both production and repair activities. The emphasis will be on the facilities allocation: which facilities ought to be totally segregated? Which structures might be partially shared and to what extent? Which services are basic and thus would be common to both activities? DESIGN OF A SHIPYARD FACILITY LAYOUT FOR SHIP PRODUCTION 4.1 Features and Data Determination

4.1.1 - Shipyard Size and Features To be economically viable, the development of a new shipyard requires the fulfilment of five basic requirements: existence of potential customers, availability of skilled workforce, financial funding, selection of a suitable product mix, and implementation of an efficient production process. For the case under examination, the shipyard in project is assumed to be located in a developing economy area such as North Africa and mainly intended to build small tonnage specialised ships with high added value, as it could target the segment of small patrol naval vessels, with a displacement ranging from 1000 to 5000 Tonnes deadweight. The work organisation is then expected to be labour intensive. Consequently there are no requirements for high productivity levels. The shipyard in project may be assumed to be equipped with building capacities to handle simultaneously three ships in progress. The erection area may be expected to comprise of at least three distinct building platforms, which may consist of berths, graving docks or even a synchrolift depending on the site configuration and the future prospects of the shipyard. Besides ships are expected to be launched, completed and delivered at different dates, thus it is likely that two piers or quays for afloat outfitting operations should fill the requirement.


4.1.2 - Work Organisation One of the basic assumptions is that there are no site constraints as there are no previous facilities to integrate within the newly developed one. Consequently, the layout may be designed according to the straight continuous flows patterns of materials, personnel and information. Actually the straight-line model is the simplest one but many external factors may prevent its implementation. The general trend is to transfer as much work as possible into the steel hall and the various workshops in order to minimise works contents and times on the erection area.

4.1.3 - Product Mix and Volumes of Production

The product mix would consist of high added value small tonnage specialised ships with displacement ranging from 1000 to 5000 tonnes deadweight. The average building period for the former types and sizes is around 12 months, except for naval ships. In the most optimistic case, the shipyard is expected to have continuously three ships in progress over a three years period, which is considered as a base reference for the estimation of the yearly throughput (Bruce and Clark, 1992). The productivity and therefore the number of employees will be estimated upon these assumptions. Therefore a broad workload planning for the shipyard is proposed in table 1.

Ship 1st year 2nd year 3rd year

A B C D E

Preparation and prefabrication Hull construction and advanced outfitting Launch and final outfitting

Table 1- Assumed production planning Three ships which detailed characteristics are summarised in appendix 2 were chosen as models. Though they are of different types, they are characterised by the same construction pattern: a long uniform main body comprised of holds enclosed between a stern castle and a fore body. Assuming a full orderbook, the shipyard would complete the building of 5 ships over 3 years, consisting of 2 reefers, 2 chemical carriers and 1 combined cargo.

4.1.4 - Productivity Targets

Productivity is usually defined as the output from a process related to the input to that process. Since the 1960s, various measures have been used, but the increase of the number of ships types and sizes rendered those metrics inadequate to relate shipyards with their respective productions and productivities. The estimation of the expected productivity of the shipyard in project will be achieved according to the approach proposed by Lamb and Hellesoy (Lamb and Hellesoy, 2002). The CGT data (Compound Gross Tons) of the models in the mix are obtained by means of the CGT Coefficients for ships of various types and sizes which were first proposed by Bruce and Clark (Bruce and Clark, 1992) (Appendix 4).

4.1.5 - The Outsourcing Strategy

Most of the heavy industries outsource and subcontract several stages of their production processes. These purchased items and services contribute considerably to the added value of the final product. Based on a zero profits evaluation for the company, materials used for onboard outfitting and work subcontracted either out of and at the yard, respectively accounts for 35.3 % and 5.8 % of the added value (Koenig, 2002). More generally


outsourced products and services account for 50% to 80% of the total cost of a new project in shipbuilding industry. Consequently there must be a strategic approach to make-vs.-buy decision-making process. Products and services likely to be outsourced must be carefully and thoroughly evaluated because outsourcing will inevitably entail reduction in self-sufficiency and flexibility of the shipyard (Wilson et al., 2001).

4.1.6 Production Layout Main Components In the last decade, the American board in charge of the NSRP program conducted a comprehensive survey of six among the most competitive Asian shipyards (Baba, 2000). Some operations were identified as basic and are commonly implemented in modern commercial shipyards. These operations relate mainly to: Steelworks, Outfitting and storage operations, Pre-erection activities, Ship construction and outfitting. Given the preceding considerations and the assumptions made about the outsourcing strategy, the facilities to be retained within the shipyard in project may principally consist of:

1. A steel stockyard 2. A steelwork hall 3. An Outfitting centre 4. A pipe shop 5. A general-purpose shop 6. A paint shop 7. A warehouse 8. A units and blocks storage area 9. An erection area consisting of three

platforms 10. Outfitting quays 11. Lifting and handling installations

12. One building accommodating the production supporting services

13. One building accommodating the management and administrative offices

14. A health and medical service 15. A training centre 16. A building accommodating the

catering services 17. A transportation station 18. A parking

4.2 Shipbuilding Facility Layout Design

4.2.1 - Flows Analysis of a Production Facility Flow analysis is of the utmost importance in the framework of a layout design. Flow analysis deals with quantitative and qualitative assessment of movements of materials, personnel and information between facilities. Yet the emphasis is on the flow of materials since the layout must be optimised for the most efficient flows of products (Francis and White, 1974). The Activity Relationship Chart (REL) was first proposed by Muther (Muther, 1973) and rather than quantitative values, it contemplates alternative qualitative parameters which relate to facilities interrelations. This proves very useful when detailed quantitative data are not available at the design stage, or when the matter concerns services that do not deal with flows of materials such as supporting or auxiliary services. Muther defined the rating of closeness between facilities and as a rule of thumb, most of the layout planners suggest to roughly comply with the proportions of the various rated relationships as reported in table 2:

Table 2 - Closeness rating labels and recommended proportions (Muther, 1973)

Closeness rating % of total number of relations Reasons for desired closeness

A = Absolutely necessary < 5 E = Especially important < 10 I = Important < 15 O = Ordinary closeness < 20 U = Unimportant > 50 X = Undesirable < 5

1. Sequence of work flow 2. Share of equipment 3. Better material handling and

transfer 4. Environmental disturbances 5. etc


Establishing the rates of the desired closeness between all the facilities is a laborious process. It is a subjective approach, which requires minimum background and experience about the activities to be implemented within the projected facilities. The flows of materials, personnel and information were taken into consideration. The Activity Relationship Chart (REL) was compiled and reported in table 3.

4.2.2 Production Activity Relationship (REL) Diagram

The actual layout is primarily based on the Activity Relationship Diagram that results from the compilation of the REL chart. Actually, the REL diagram constitutes an anticipated broad configuration of the final layout. The procedure generates a set of feasible alternatives which should be traded off with respect to the space requirements, modifying considerations and practical limitations as recommended by Muther. Subsequently, the compilation of the REL chart yielded the Activity Relationships diagram using the symbols of the ASME and the rates coding as defined by Muther (appendix 3). The various rated relations are diagrammed according to Muthers procedure. At each step, the diagram must be rearranged seeking the best compromise. It may require several attempts before achieving a satisfactory result. The REL diagram for the case study is reproduced in figure 5. This algorithm is deterministic, thus it generates always the same layout from the same original data.

4.2.3 - Space Requirements of a Production Facility

Once the REL diagram has been completed, the space allocations of the various facilities are required to initiate the drawing of the actual layout. Fitting into the REL diagram figures of those spaces drawn to the scale 1/500x104 yields the Space Relationship Diagram (figure 6) which actually represents a crude layout, i.e. the basis that requires adjustment and rearrangement to obtain the final layout configuration. The results are summarised in appendix 4.

4.2.4 - Production Layout Design

The Space REL Diagram yields the actual layout when the various facilities are appropriately joined together. Then it needs to be adjusted and rearranged according to specific modifying considerations and/or practical limitations (Muther, 1973), which essentially pertain to the site and facilities peculiarities. It is the most creative phase of the whole process and often it involves the personnel who will be in charge of the installation and operation of the designed layout. The final layout configuration will be selected according to explicit requirements pertaining to its future utilisation. Different layout alternatives, which one of them is reported in figure 7, were generated in order to highlight the various possibilities that are available to the planner. In each case, the basic idea consisted of concentrating the facilities into three main areas: a preparation and prefabrication area, a construction area, and an administrative area and other services.


Table 3- Activity Relationship Chart of a production facility


1

3

2

8 11 4

5

6

14

15

12

13

16 17 7

3 9

10 10

Figure 5 - Production layout: Activity Relationships Diagram

Legend 1 Steel stockyard 2 Steel work hall 3 Outfitting centre 4 Pipe shop 5 General purpose shop 6 Paint shop 7 Warehouse 8 Units and blocks storage areas

9 Erection areas

10 Lifting and handling installations 11 Quays 12 Production supporting services 13 Training centre 14 Managers and administrative offices 15 Transportation station, parking 16 Catering services 17 Health and medical service


11

9

10

8

6

7 1

1

3

2

1

4

5

1

1 15

17

Figure 6 Production layout: Space Relationship Diagram


6

712

3

2

1

4 5

15

15

8 8 8

9

1

0

13

14 16

17

1

0

1

1

1

0

1

1

9

1

0

9

1

0

Legend 1 Steel stockyard 2 Steel work hall 3 Outfitting centre 4 Pipe shop 5 General purpose shop 6 Paint shop 7 Warehouse 8 Units and blocks storage areas 9 Erection areas

10 Lifting and handling installations 11 Quays 12 Production supporting services 13 Training centre 14 Managers and administrative offices 15 Transportation station, parking 16 Catering services 17 Health and medical service

Pathways

Figure 7 - Production layout: 1st configuration alternative


DESIGN OF A SHIPYARD FACILITY LAYOUT FOR SHIP REPAIR 5.1 - Features and Data Determination

5.1.1 - Shiprepair Activity Features Unlike shipbuilding, repair works are of the job shop form, thus less repeatable from one case to another and predictions and planning reveal very arduous. It emerges that the only repair jobs that may be assumed approximately predictable and thus manageable are those relating to docking activities. The emphasis would then be put on the dry-docking facilities while providing only basic workshops resources that are commonly required in shiprepair.

5.1.2 - Capacity Planning in Ship Repair There is no standard methodology or procedure for determining the capacities of a repair yard in the design stage. A practice that is common within the sector consists of developing capacities for defined configurations only, which pertain to the targeted market segment. However given the unsteadiness of the fluctuating demand, most of the repair yards would implement only a fraction of the theoretically required repair capacities (Drewry, 2001).

5.1.3 Repair Workload of the Case Study The repair workload that will be adopted for the case study will consist of types of ships, and frequencies of attendance that relate to an Algerian shipyard which had been considered in the framework of an MSc Thesis carried out at the School of Marine technology of the University of Newcastle in 1989 (Zenasni, 1989). The concerned shipyard basically undertakes:

- small shipbuilding both naval and merchant - naval shiprepair for the Algerian navy - merchant shiprepair up to certain sizes and tonnages.

5.1.4 - Docking and Berthing Capacities Analysis of the Case Study

Given the variety of the calling population of ships, assumptions have to be made about the dry-docking and berthing capacities. The aim is to obtain the best combination of facilities of different sizes in order to achieve an optimum and effective flexibility of the resources. Naval vessels were first subdivided into three and then four categories fitting within two configurations of dry-docking facilities, viz.: 40 m, 70 m, 110 m and 30 m, 60 m, 90 m, 110 m respectively. Merchant fleet data were compiled too, taking into account both minimum and maximum frequencies of attendance to the shiprepair yard. Four categories of dry-docking facilities were assumed with lengths respectively of 100 m, 150 m, 200 m, and 300 m. Many combinations were tried until a maximum utilisation of each single facility was achieved. Results for dry-docking and berthing requirements were achieved for average utilisation of the docking facilities and maximum utilisation of the berthing facilities and reported in tables 4, 5 and 6. Shadowed squares indicate shifting of units of a given category towards docking facilities of a higher category.

5.1.5 Repair Layout Main Components

Some basic facilities equipped with typical machinery and tools that are commonly implemented in shiprepair yards were selected, viz.:

1. Docking facilities to be defined later, whether they would consist of a synchrolift, graving docks or floating docks

2. Berths 3. A metal shop: Hull works, pipe

works, galvanizing works 4. An electrical shop 5. A carpenter shop 6. A paint shop 7. Afloat repair shop

8. Lifting and handling installation. 9. Deballasting and sludge treatment

plant. 10. Management and administrative

offices 11. Technical services 12. A health and medical service 13. A training centre 14. catering services 15. A transportation station 16. A parking


5.2 Shiprepair Facility Layout Design 5.2.1 - Flows Analysis of a Repair Facility

Repair works are essentially labour intensive which occur mostly onboard ships. Thus the volumes of materials that are transferred and their related occurrences cannot be reliably defined in advance.

5.2.2 Repair Activity Relationship (REL) Diagram Based on the preceding flows analyses the Activity Relationship (REL) Chart of a repair facility was compiled. Subsequently the rated relationships were diagrammed according to the same techniques and making use of the same principles that were thoroughly described during the analysis of the shipbuilding case.

5.2.3 - Space Requirements of a Repair Facility Given the preceding considerations relating to the uncertainties pertaining to repair works demand, any attempt to approximate targeted productivities and manhours may reveal intractable and the subsequent results unreliable. The determination of the spaces of the various workshops and supporting services was then based on a comparative analysis with similar facilities from different repair yards across the world as reported in appendix 5.

5.2.4 - Repair Space Relationships Diagram

The surfaces of the various facilities were drawn to the scale 1/500x104 and fitted into the Activity REL Diagram of a repair facility yielding the corresponding Space Relationship Diagram as reproduced in figure 8.

5.2.5 - Repair Layout Design

Similarly to the shipbuilding yard case, the Space REL Diagram yields the actual layout when the various facilities are appropriately arranged and joined together. Many configurations were proposed in order to highlight the wide range of possibilities that are offered to planner. Figure 9 reproduces one alternative as an example. Further to the synchrolift, two docking facilities of 150 m and 200 m respectively are required. These could consist either of graving docks, floating docks or a combination of the two types. The final choice would be dictated by diverse factors such as: development prospects of the company, investment costs, land availability on the site, timing of realisation, etc For the case study, two graving docks were assumed. Should two floating docks be considered, the only difference would reside in a different land utilisation since the floating docks would be secured in the water plane of the yard next to some berth.


Table 4 - Average utilisation of the docking installations of a repair facility - 1st case

Months 1 2 3 4 5 6 7 8 9 10 11 12 40 70

N

a

v

a

l

v

e

s

s

e

l

s

c

a

t

e

g

o

r

i

e

s

(

m

)

110

100 150

M

e

r

c

h

a

n

t

s

h

i

p

s

c

a

t

e

g

o

r

i

e

s

(

m

)

200

Time basis=1 year Required: 2 facilities of L=40 m 3 facilities of L=70 m ==> may service for 4 months naval vessels of L=40 m 2 facilities of L=110 m ==> may service for 5 months merchant ships of L=100 m 1 facility L=150 m ==> may service for 1 months merchant ships of L=100 m 1 facility L=200m ==> may service for 6 months merchant ships of L=150 m Utilisation of facilities L=40 m and L= 70 m ~83% Utilisation of facilities L=110 m L= 150 m and L=200 m ~92% 1 month allowance for routine maintenance operations Possibilities: 1 Synchrolift of 3000 tonnes up to 5000 tonnes with 5 bays (2x110x20 + 3x70x20 ) 2 slipways of 40x10 m and D=200 tonnes 2 docking facilities of 150x30 m and D=6500 tonnes up to 10000 tonnes 1 docking facility of 200x30 m and D=12000 tonnes up to 15000 tonnes


Table 5 Average utilisation of the docking installations of a repair facility 2nd case

Months 1 2 3 4 5 6 7 8 9 10 11 12

30

60

90

N

a

v

a

l

v

e

s

s

e

l

s

c

a

t

e

g

o

r

i

e

s

(

m

)

110 100 150

M

e

r

c

h

a

n

t

s

h

i

p

s

c

a

t

e

g

o

r

i

e

s

(

m

)

200

Time basis=1 year Required: 1 facility of L=30 m 3 facilities of L=60 m ==> may service for 3 months naval vessels of L=30 m which may be grouped in pairs and utilise the 60 m facility for less than 3 months 1 facility of L=90 m 2 facilities of L=110 m ==> may service for 5 months naval vessels of L=90 m and for 6 months merchant ships of L=100 m 1 facility of L=150 m 1 facility of L=200 m ==> may service for 6 months merchant ships of L=150 m Average utilisation of all facilities 11/12 months ~ 92 % 1 month allowance for routine maintenance operations Possibilities: 1 Synchrolift of 3000 tonnes up to 5000 tonnes with 5 bays (2x110 + 1x90 + 3x60) 1 slipway of 30 x 10 m and D=100 tonnes 1 docking facility of 150x30 m and D=6500 tonnes up to 10000 tonnes 1 docking facility of 200x30 m and D=12000 tonnes up to 15000 tonnes


Table 6 Maximum utilisation of the berthing installations of a repair facility

Months 1 2 3 4 5 6 7 8 9 10 11 12 30

60

90

N

a

v

a

l

v

e

s

s

e

l

s

c

a

t

e

g

o

r

i

e

s

(

m

)

110 100 150 200

M

e

r

c

h

a

n

t

s

h

i

p

s

c

a

t

e

g

o

r

i

e

s

(

m

)

300

There are no particular restrictions concerning the required berthing capacities. Lay-up requires berth accommodation hence it is included in the berthing requirements. Berths may be fully and continuously occupied. Naval vessels have been subdivided into four categories for the flexibility of the utilisation of the berths. Merchant ships of L>250 m have been included assuming that repair works afloat may be carried. Required berths length: 2x30 + 5x60 + 3x90 + 2x110 + 150 + 300 = 1300 m subdivided for example into : 4x150 m and 2x200 m and 300 m Note: When ships are secured to berths of a higher category they require less berth-months because they may be paired: 4 berth-months of L=150 m equate 2 berth-month of L=300 m


Legend 1 Docking facilities 2 Berths 3 Steel shop 4 Machine shop 5 Electrical shop 6 Carpenter shop 7 Paint shop 8 Afloat repair shop 9 Warehouse

10 Lifting installations 11 Treatment plant 12 Administrative offices 13 Technical services 14 Health-medical service 15 Training centre 16 Catering services 17 Transportation station

and parking

Figure 8 Repair layout: Space Relationship Diagram

1

2

3

4

5

8

7 6

11

1

17

17

1

14

1

1

10

9


Design of a mixed shipyard facility layout for ship production and repair Bearing in mind the various considerations that were invoked for the selection of the facilities that ought to be retained for shipbuilding and shiprepair respectively, the aim is to define which might be shared between the two activities and which should be segregated. Consequently, the following selection was established:

- should be segregated and solely dedicated to shipbuilding:

1 a steel stockyard 2 a steelwork hall 3 an outfitting centre

4 a units and blocks storage area 5 an erection area

- should be segregated and only dedicated to shiprepair:

6 a docking area 7 a machine shop 8 an electrical shop

9 a carpenter shop 10 an afloat repair shop 11 a treatment plant

- facilities that might be shared with predominance of one type of activity:

12 pipe shop (shipbuilding) 13 a steel shop (shiprepair)

14 berths (shiprepair)

- facilities that are equally shared between the two activities:

15 a paint shop 16 a warehouse 17 lifting installations 18 administrative offices 19 technical services

20 health and medical service 21 training centre 22 transportation station and

parking. 23 catering services

All the data and assumptions of the previous two cases were adopted. The completion of the whole process yielded many configurations. One configuration alternative is reproduced in figure 10.


4

5

8

6

1

17

17

15

14

1

1

9

Dock 2 B th 1

Berth 2

Ber

th 3

Berth 7

Berth 5

Berth 6

Berth 4

3

7 11

Dock 1

Bay 1

Bay 2

Bay 3 Bay 7

Bay 6

Bay 5

Bay 4

Lifting platform

Transfer platform

Berth 1

B th 1

Figure 9 - Repair layout: a configuration alternative (making use of piers)

Legend 1 Docking facilities 2 Berths 3 Steel shop 4 Machine shop 5 Electrical shop 6 Carpenter shop 7 Paint shop 8 Afloat repair shop 9 Warehouse

10 Lifting installations 11 Treatment plant 12 Administrative offices 13 Technical services 14 Health-medical service 15 Training centre 16 Catering services 17 Transportation station

and parking


Dock 2 B th 1

Berth 2

Ber

th 3

Berth 7

Berth 5

Berth 6

Berth 4

Dock 1

Bay 1

Bay 2

Bay 3 Bay 7

Bay 6

Bay 5

Bay 4

Lifting platform

Transfer platform

Berth 1

22

2018

2 1 3

12

1516

19

21

23

7 8 10 9 11

13

4 4 4

5

17

14

5

17

5

17

14

Figure 10 An example of layout configuration of a mixed shipyard facility


Conclusion The present study aimed to investigate whether a small shipyard intended to produce ships of between 1000 and 5000 DWT could supplement this activity with a substantial repair workload without disrupting its work organisation? Production processes are rather different than repair and maintenance works. Their needs are different and often irreconcilable. From the investigation it emerged that the implementation of Group Technology concepts profoundly modified the work organisation within shipyards as it shaped their respective layouts. Its generalisation was motivated by the need to reduce production costs whilst maximising the resources utilisation. For the purpose of the study, three cases were considered in sequence: a production layout, a repair layout and a mixed layout designed to handle both building and repair activities. In either case, the systematic layout planning method proposed by Muther was applied. It consists of a procedure that thoroughly contemplates all the production processes of the enterprise starting from the material procurement and taking into account the actual prevailing environment. The technique reveals robust and efficient since it can address situations where the available data are neither sufficiently detailed nor exhaustive as it may be the case at an early stage of a project. In this way, though flows are important they do not impact alone the layout pattern. Therefore other supporting services that do not deal with volumes of flows might be taken into consideration such as the purchasing or the production engineering department for instance. The two first cases were separately developed upon basic assumptions regarding the product mix, the repair workload and the respective work organisations. A thorough analysis of the practices implemented in shipyards of similar sizes and features was achieved. Subsequently the study of a mixed layout was developed by merging the results of the previous two cases, analysing which resources ought to be segregated, or partially or totally shared based on their respective impact on the work processes. Various configurations alternatives were then generated in order to illustrate the wide range of possibilities that are offered to the planner. The selected layouts exhibit forms and arrangements that are characteristic of the correspondent types of activity. The main limitations to this work reside in the various assumptions essentially relating to the productivity targets and the flows of elements that were required in order to achieve the diverse analyses. Nonetheless the emphasis was on the application of a methodology of layout design based on the procedure outlined by Muther which reveals a perfectly efficient layout planning method adapted for the very early stage of a new project when quantitative data are only broadly defined.


References

1. Apple, J. M. (1991). Plant layout and material handling. Malabar, Fla., Krieger. 2. Baba, Koichi, (2000). Production technology survey of selected Asian shipyards.

NSRP, Maritech Engineering Japan, November 1, 2001, from website www.nsrp.org/documents/asian_benchmarking.pdf

3. Bruce, G. J. and Garrard, I. (1999). The business of shipbuilding. Honk Kong, Llp. 4. Bruce, G., Clark, J., (1992). Productivity measures as a tool for performance

improvement. The Royal Institution of Naval Architects, Spring Meetings, 27 April 1992, paper No 2.

5. Chirillo, D. L., (1979). Outfit planning. NSRP, US Department of Commerce. 6. Drewry, (2001). Global Shiprepair Market Outlook to 2005. Shipping Consultants

Publications, June 2001, from website www.drewry.co.uk/frame2.phtml?loc= info/mr049.phtml on 30/06/2003

7. Francis, R. L., and White, J. A., (1974). Facility layout and location An analytical approach. Prentice-Hall Inc., Englewoods Cliffs, New Jersey.

8. Garcia L., F. V., Torroja, J. (1994). The role of CAD/CAE/CAM in engineering for production. Proceedings of the 8th ICCAS International Conference on Computer Applications in Shipbuilding, Sept. 5-9, 1994, Bremen, Germany, Berry Rasmusson Reklam AB.

9. Koenig, P. C., (2002). Technical and economic breakdown of value added in shipbuilding. Journal of Ship Production, Vol. 18, No. 1, February 2002, pp. 13-18.

10. Lamb, T., and Hellesoy, A., (2002). A shipbuilding productivity predictor. Journal of Ship Production, Vol. 18, No. 2, May 2002, pp. 79-85.

11. Muther, R. (1973). Systematic layout planning. Cahners books. 12. Storch, R. L., Hammon, C. P., et al. (1988). Ship production. Centreville, Md., Cornell

Maritime Press. 13. Wilson, V., Wennberg, P., DeGraw, K., and Fleischer, M., (2001). An improved Make

versus Buy strategy for future material acquisition. Journal of Ship Production, Vol. 17, No. 2, May 2001, pp. 87-91.

14. Zenasni, M. (1989). Domestic ship repair yard and improvement strategy. MSc Thesis, Department of Marine Technology, University of Newcastle upon Tyne, Sep 1989


Appendices Appendix 1

The following figures illustrate how far-eastern shipyards which pioneered in implementing Group Technology considerably improved their performances.

Figure 1 Performance comparison of some shipbuilding leading nations (NSRP,

2001)

Figure 2 World market share of the Far East shipbuilders as a result of their

competitiveness (Lloyds Register, 2003)


Appendix 2 Main characteristics of the ship models of the production mix

Name Kaisers No. 7 Regina Marie Christine

Reference The Reefer Register 2003 Clarkson, 2003

The Chemical Register 2003 Clarkson, 2003

Significant small vessels of 1991 RINA, 1991

Type Reefer Fish Carrier Chemical and Oil Carrier

Forest Products/Cargo Vessel

Status In service In service In service Owner country Taiwan Belgium Netherlands Flag Honduras Luxembourg n.a . Year of build 1980 1987 1991

Builder Kishimoto Zosen (Japan) Schpsw. Lanser (Netherlands)

Niestern Sander BV (Netherlands)

Length overall 83 m 109.9 m 87.96 m Length between perpendiculars 77.02 m 106.7 m 84.93 m

Beam 13.21 m 11.34 m 12.5 m Draught 5.01 m 3.29 m 5.30 m NT 1872 1731 1289 Dwt 2028 2500 3284 Classification Society NKK BV LR

Number of holds/tanks 3 12

1 hold comprised of 9 bays

CGT values of the three ship models comprising the production mix

N. Type DWT (Tonnes) GT CGT

Coefficient CGT

1 Reefer 2028 1872 2.05 3837.6 2 Chemical carrier 2500 1731 1.70 2942.7 3 Combined cargo 3284 2561 1.60 4097.6


Appendix 3 - ASME symbols and Muther's coding for the Activity REL diagram

Symbol Activity/Facility Color Rating Value Nbr of

lines Color

Treatment, Sub-assembly, Assembly

Green Red

A 4

Red

Transport related Orange

E 3

Orange

Storage, Warehouses Orange

I 2

Green

Hold areas Orange

O 1

Blue

Services and supporting activities

Blue

U 0

Office, Administration Grey

X -1

Brown

Inspection, Check areas Blue


Appendix 4 Space requirements of a production facility

Facility Employees Density Floorspace (m2) Steel stockyard (1000 tonnes) 2 tonnes/m2 2000 Steelwork hall 40 100 m2/worker 4000Outfitting centre 30 60 m2/worker 1800Pipe shop 20 60 m2/worker 1200General purpose shop 10 60 m2/worker 600Paint shop ( 2 cells of 20x20 m) 15 2x20x20 = 800Warehouse 5 320 m2/worker 1600Units and blocks storage areas (for 3 grand blocks of 20x20 m)

3x20x20 = 1200

Erection areas (for 3 ships) 130x20/platform 3x2600Lifting installations 6 4x130x10Quays (to secure at least 2 ships of length up to 130 m)

2x130x20 =2x2600

Production supporting services 27 15 m2/worker ~ 400Training centre 12 30 m2/trainee ~ 400Managers-Administrative offices

24 15 m2/worker ~ 400

Transportation station: covered facility including workshop, office, storage room and shelter for handling equipment

5 ~1000

Parking for 100 private cars 12x100+8x50 = 1600

Catering services 10 400Health and medical service 3 100

Total 207 35700 (excluded the circulation pathways)


Appendix 5 Space requirements of a repair facility

N. Facility Floorspace (m2) 1 Docking facilities 29500 2 Berths 26000 3 Steel shop 5000 4 Machine shop 1000 5 Electrical shop 500 6 Carpenter shop 500 7 Paint shop 500 8 Afloat repair shop 500 9 Warehouse 1600 10 Lifting installations 23300 11 Treatment plant 500 12 Administrative offices 400 13 Technical services 400 14 Health-medical service 100 15 Training centre 400

Transportation station 1000 16 Parking 1600 17 Catering services 400

Total 92300