-
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
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- 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.
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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
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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)
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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
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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.
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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
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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
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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.
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Table 3- Activity Relationship Chart of a production
facility
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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
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11
9
10
8
6
7 1
1
3
2
1
4
5
1
1 15
17
Figure 6 Production layout: Space Relationship Diagram
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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
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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
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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.
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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
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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
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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
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Symposium International : Qualit et Maintenance au Service de
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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
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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.
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Symposium International : Qualit et Maintenance au Service de
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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
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Symposium International : Qualit et Maintenance au Service de
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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
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Symposium International : Qualit et Maintenance au Service de
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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.
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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
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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)
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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
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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
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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)
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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
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