Using LINUX
at Lectra-Systèmes

Pierre Ficheux (pierre@rd.lectra.fr)
(Juillet 1996)

Abstract

This article is the story of the choice and the use of LINUX by an important industrial company. The opinions expressed in this article are those of the author and not of the Lectra-Systèmes company.

Contents

Who is Lectra Systèmes ?

Lectra Systèmes is one of two world leaders in the design and creation of the CAM solution, CAD/CAM and cutting machines mainly for the footwear and apparel industry. The headquarters of this company are in Cestas, in the suburbs of Bordeaux (France). Five hundred people work here, 150 of which are in the Research and Development department.

I am in charge of the systems development in the R&D Department. The system group is in charge of all developments that concern base systems (installation procedures, graphic libraries, tools).

Since the 1980's, Lectra has developed its own computers based on Motorola 680x0 processors. The main part of the park installed (approx. 3000 customers, 80% abroad) uses an mono-task, prorietary operating system, written in 680x0 called MILOS for "Micro Lectra Operating System".

Why use UNIX® ?

A few years ago, Lectra started to become interested in data base systems requiring the use of a more powerful system which should be multi-task and multi-user. After some teething problems with the Unix-like, the choice wavered to implementing the UNIX® AT&T System V3.2 for 680x0 architecture. The small team of which I am a member have managed to port the Unisoft sources as well as the X Window System graphic environment.

Lectra then decided to develop a new line of computers based on 68040 processors, much more powerful than the 68030. The operating system used was the UNIX® USL SVR4.0 version and another port was made.

Although this task proved to be very interesting we were still persuaded that this computer (named OpenCad) would be the last one designed from scratch by the R&D teams. A few people continued to show interest but working for series that were too small were no longer able to continue fighting in a hardware market that was being lead by race against power, low cost prices...

1995, Lectra's cultural revolution

Despite OpenCad's commercial success at our customers, Lectra's management quite rightly decided to launch the development of a completely new range of products that were mainly targeted at an Intel 486 and Pentium architecture still with a UNIX® environment and X Window system. The data base applications using many resources would on the other hand be targeted to SUN SPARC architecture.

After some comparative tests between the different UNIX® versions on PC, it was decided to use LINUX which proved to be sturdy, have a high performance and at the right price. In having the sources of the system available proved to be advantageous for LINUX as we use many special peripherals to which the adaptation would be much more difficult on a UNIX® owner.

Developments under LINUX

The system having been chosen, now meant adapting LINUX to an industrial solution. It is quite clear that UNIX® (and therefore LINUX) is slightly more difficult for a final operator to use. This adaptation must be done in two stages :

Installation procedure

The Lectra distribution uses the same principles as the distributions to develop (2 boot floppies and a CD-ROM). The installation screens use dialog-0.3, which has proved to be extremely simple and powerful when it comes to creating a series of installation screens. Here is the main Lectra LINUX installation window :

The main advantage when choosing LINUX in this domain is that it has the possibility of creating an installation procedure that is extremely precise (only what is required is installed) and it is therefore very quick (the current Lectra Desktop version takes less than 10 minutes to install on a Pentium 120).
In comparison, the same desktop version on a Solaris® target takes nearly an hour as it necessary to install the Solaris® CD first followed by Solaris® patches then last of all the Lectra Desktop...

The different packages are managed as ISO-9660 files (with Rock-Ridge extension) from a LINUX structure using the mkisofs program, then the ISO images are engraved on the master CD using a PC under ...Windows®.

OpenPartner® Desktop

The first graphic applications under MILOS had a very spartan look, this was due to the weak performances of the graphic controllers at that time (beginning of the 1980's). The screens, even although they were graphic could only manage 16 colours and moreover they did not use multi-windows. Hastened by competition, in 1990 Lectra decided to develop the graphic interfaces to a multi-window system facilitating the operator's work for basic operations such as launching applications or working with files. This tool called OpenPartner® was initially developed for the MILOS target using a low level owner library (similar to Xlib calls). The structure of the interface seemed very similar to that of the Xt/Intrinsics Widgets hierarchy, this in view of a next port and some towards the UNIX®/X11 environment.

The port of OpenPartner to the UNIX® environment accompanies the addition of the administration functions of the station by a privileged user, in particular :

Here is an example of the main window in the OpenPartner environment with the package management utility (P-Manager).

One of the important tasks was to develop a printer management system that could be extended and was easy to use. Even when supporting UNIX®, we have to admit that the print system on Windows® or even MaCOS is much clearer and easier to use than on our favourite OS. Furthermore, all the printers currently commercialised are supplied with their own Windows® or MacOS® driver.

Our print system (operating client/server) uses the Ghostscript program which manages different types of printers (PCL, PostScript, raster) on varied connections (serial line, Centronics, network, SCSI). A graphic tool integrated in OpenPartner (I-Manager) is used to select only the printer characteristics that are used (the list then appears in the print selector of Lectra applications).

Lectra applications

The applications are intended for the industrial professionals in Apparel. The garment is designed in various stages and corresponds to different trades. One of the industrial characteristics in Apparel is the resort that is made to sub-contractors and delocalisation. Various stages of the apparel could be realised by the apparel maker yet production could be sub-contracted to another country.

Some countries only deal with the design or only the production and supply several major marks ....

The result of this situation for a company such as Lectra is that it is absolutely essential to design open software as very few customers will buy a complete series and it is therefore necessary to know how to communicate with competing software.

Another important constraint is to support lots of languages such as japanese, chinese or russian. This is done by using tools such as asiatic front-end-processor under X11.

On first approach, we could remove the following stages when designing a garment.

Design

The designer has to create a garment model like an artistic drawing. His/her work is mainly based on the choice of shapes, colours, types of fabrics that can be used.
The advantages in having a data processing tool is clear. Other than the possibility of working on an "electronic sheet", the software enables the pattern maker to import fabric motifs (in an electronic form or even using a scanner), to file the suggestions of different collections, to make fabric simulations in 2D or 3D.

The ProStyle® software offers above all the previous functions on a high performance LINUX PC (Pentium 120 with Diamond Stealth S3-968 graphic board, 16 million colours). Sublimation printouts (mostly SCSI) are also available. The software also concerns the Silicon Graphics architecture.

Pattern making

The pattern makers must create the pattern of the garment (the plan with quotation) from the information given by the designer. He/she must also manage the different sizes available (grading). The information of this phase is one of the most interesting (with the marker) as is has a high turn-over (the number of patterns produced).

Here is a view of the initial screen of the Modaris® application, Lectra application designed for the pattern maker :

The marker

The marker maker must optimise the material use (the piece of fabric called width) depending on the list of pieces given by the pattern maker. The quality of the work of a marker maker is expressed in the efficiency of a marker (which corresponds to the material quantity used in relation to the material loss). A good marker had an average efficiency of 85% meaning that 15% of the material is lost. A gain of a few tenths of % in production can have important economic consequences when it concerns costly materials such as leather or high quality fabrics.

The Diamino® software working on LINUX PC has a semiautomatic marker which makes work easier for the marker maker as it facilitates positioning the piece. It also has a new automatic marking module (which marks all the pieces on the width without any manual intervention) of which the performances today are nearing 2% of one of a professional marker.

With the current PC architecture it is now possible to obtain such a result at a very attractive price whereas only a few years ago, the economic existence of an efficient module for the automatic marker was impossible due to material costs. Below is an evolution of the automatic marker making performances depending on the architecture used (time in seconds).

The first two columns concern the old Lectra X400 and X410 computers respectively based on the 68030 and 68040 processors operating under System V R4.

The 3 PC's (DX2/66, Pentium75, Pentium120,) operating under LINUX-1.2.13.

The cut and plot

The cut of the pieces can be done by hand or with a cutting machine which has a better turnover advantage. In some cases, you do not cut the pieces but just plot the shapes on a paper support to give to the sub-contractor.

The previous range of products from Lectra required the purchase of a computer per plotter or cutter as the MILOS operating system of the computers was mono-task (the plotters and cutters were run by serial channel).

The new VigiPrint® software developed under LINUX controls about ten plotters simultaneous meaning a save in cost that should not be neglected when purchasing the configuration together with much more facility in controlling the plot (managing the plotters on the same screen). The number of cutters managed by the software is limited to only one for security reasons (the operator must be attentive to any blade break or other anomaly). The cut is made either with a blade (most common), a high pressure water jet (2000 bars) or a laser beam.

The production management

It enables managing all the data manipulated by the previous trades. In this way, it is possible to define for a given product the production follow-up folders which are filed in the relational data bases. These bases make it possible to file various elements of a previous collection and re-use them in a current collection (MasterLink and StyleBinder software).

Below a screen from the StyleBinder software under LINUX.

Problems encountered

The main problem is the integration of new peripherals, the PC world being literally in the hands of Microsoft. Some peripheral constructors (mainly small constructors) are attentive to the LINUX evolution and collaborate easily when elaborating drivers. The large structures are much more difficult to convince and they are often hidden behind the imperatives of "marketing strategy" refusing to supply the information required. Generally they refuse to accept any solution other than Microsoft® especially when it concerns technical supports, the development teams rarely being directly accessible in such structures.

However, the problems encountered are limited in number :

Other subjects have caused us (and are sometimes still causing us) a few worries.

Conclusion

The experience of the new Lectra range shows that is possible to build an industrial solution under LINUX. The system is stable, powerful, study and it is possible to gather a wide range of information thanks to Internet, which has proved to have the highest performance in technical support. Just by having system sources makes it possible to develop more functions more easily (material drivers or individual protocols, specific file-systems).

The new orientations which were announced during the last LINUX congress in Berlin has (improvement of the Virtual File System, Optimisation of the EXT2 file system, WABI Windows® emulator, multi-processor, adoption of LINUX by Digital) assured us that LINUX has acquired much industrial maturity.

Furthermore, the choice of a PC platform enables offering the customer the possibility to have the industrial and bureautic applications on the same machine (with LINUX/Windows® double boot). The performant emulation of Windows® will most likely be an important asset for the generalisation of LINUX in the industrial desktop solutions.