[Up][Next]
Case 1: Design in Seven Days
Partners
Purpose
Design in 7 Days is a vision for the future way of designing highly
complex, one-off products. In 7 days, all major viewpoints in the design
process shall be known, including their consequences and mutual influences. All
major aspects shall be known in sufficient detail to make the decisions that
determine all life cycle phases for the product. This includes full knowledge
about committed cost, timing and environmental impacts.
Major Activities and Results
COT Case 1 is organized into a number of work categories: Pilot projects,
database projects, object-relational modeling, patterns and
frameworks, and introduction of object technology. In the
following we will present these activities.
Pilot Projects
- Power Prediction Tool.
- Power prediction (PP) is very important in the early phases of the design. A
customer usually has a requirement for the final cruise speed. However the
contract is typically signed before the exact shape of the hull is
determined. Therefore accurate estimates based on the main dimensions of a
ship is necessary.
DMI and OSS have described a vision for a distributed PP tool. The intention
is to develop a tool that can be used over the Internet with access to a
number of databases containing both model and sea trial data. A number of
problems arise with this vision because the owners of the databases typically
regard the contents of these as confidential. This will require that the users
of such a tool are unable to uncover the actual data stored in the databases
but nevertheless are able to make some sort of queries. Another problem is the
reverse--a user typically would not allow the owner of the databases (which
most likely is another company) to know the dimensions of a new ship.
A prototype for the PP tool has been developed. The prototype is based on
a Java server and a Java client (an applet). The client and server
communicates using Java Remote Method Invocation (RMI)
- Assembly Plan for Grand Blocks in the dry block.
-
During the production phase large sections are brought to
the assembly hall in conjunction with the dry dock. Here the sections are
assembled to the largest steel elements constructed on land to be placed as
part of the ship in the dry dock, the so-called grand blocks (GB's). The grand
blocks are lifted into the dry dock by means of a gantry crane. This is the
largest crane at OSS (can lift up to 800 tonnes) and it is the only crane with
capacity to lift grand blocks. The GB's are lifted one at a time, transported
into the place in the ship where they are welded to the part of the ship
already assembled. The welding of a GB into the ship falls in two parts. The
first part is during the fastening of the GB to the ship. This requires that
the GB is held by the crane during the welding. The second part of the welding
does not require the use of the crane. This part is to finish the assembling
of the GB to the ship. I.e. after the fastening of a GB the crane can be used
to lift the next GB into the dry dock, but it might e.g. not be possible to
fasten this GB to the previous GB because the previous GB might only be stable
enough to hold itself. This means, that the order in which the GB's are lifted
into the dry dock is constrained by many factors, including the load of the
the gantry crane and the part of the ship already assembled.
It is the opinion of DIKU and the people at OSS responsible for the assembly
plan that standard planning tools are not flexible enough to describe and
handle such complicated constraints. Therefore we are developing a prototype
for handling assembly plans for grand blocks in the dry dock. The prototype
has graphical user interface that displays grand-blocks and constraints. For
each constraint the time for moving the block, fastening the block, and
welding the block is displayed. In addition the time needed to shift lifting
gear are computed (depends on which gear was used when the previous GB was lifted).
For each day the workload is computed.
The prototype enforces the constraints.
The prototype can optimize the
erection sequence of the GB to minimize the time used in the dry dock. However
this is only one criteria for optimizing the erection sequence. We are considering the following criterias.
- Total time in dry dock should be minimized.
- The workload should be distributed evenly.
- The erection sequence should be tolerant toward delays in individual
tasks. This can be obtained by adding a few days of slack. Given N days of
slack we want to minimize the effect of delays of individual tasks.
Introducing Object-Oriented Technology into Companies
The development of the Power Prediction Tool prototype was combined with
mentoring. This means that DMI can continue to develop the Power Prediction
Tool prototype with minimal assistance from DIKU.
CAD system
OSS is involved in the development of a large component based CAD
system. Important goals are to increase the level of concurrency especially in
the early phases of the design and to enable 'copy-and-paste' of ship
structures and systems including semantics and interfaces from existing ships
into new designs.
To bring us closer to the D7D vision the system will have to integrate versioning,
cooperative concurrency control, and copy-semantics.
Papers
Contact persons
- Eric Jul
DIKU
Universitetsparken 1
DK-2100 Copenhagen East
Phone: +45 35 32 14 14
e-mail: eric@diku.dk
- Michael MacDonald Arnskov
Danish Maritime Institute
Hjortekærsvej 99
Lyngby
DK-2700 Lyngby
Phone: +45 45 93 25 66-276
e-mail: mma@danmar.dk
- Jan Tuxen
Odense Steel Shipyard
Postboks 176
DK-5100 Odense C
Phone: +45 63 97 10 30
e-mail: jat@oss.dk
[Up]
[Next]
Webmaster: Eric Jul, eric@diku.dk.
Last updated Wed Sep 8 16:06:22 METDST 1999