Introduction

The recent release of MicroStation V8, the most significant release to date in the evolution of Bentley's MicroStation, provides a number of fundamental changes that have provoked feelings of both excitement and apprehension. One is the extension of the DGN file format to remove the limitations previously imposed by the v7 format, another is the prospect of transparent compatibility with dwg files. We’ve heard the marketing hype, but how will upgrading to v8 affect us all in real-life? The advantages of adopting the new technology are clearly recognisable, but the potential for unexpected bugs and management problems are often a deterrent. In an industry where technology is rapidly changing, it is vital to stay abreast of the advances, and so sometimes we have to confront the challenge and realise the business benefits. It is important to balance this with the risk of jeopardising live project data or causing huge disruption and expense to the company in the process; the secret to a successful upgrade has to be in the pre-planning and testing of the software prior to complete roll-out. Time should be set aside to test the functionality and stability of the software with consideration as to whether it will actually increase productivity and enhance the day-to-day use of CAD for the majority of its users. 

We decided to plan Whitby Bird’s upgrade from MicroStation/J to v8 around the aspects of the existing system and CAD standards that we thought would need addressing. From this we were able to plan our schedule for investigating these issues and allow time to produce the necessary results. The areas that we’d anticipated would need particular attention were:

• Interfaces
• Seedfiles
• Cell Libraries
• Custom Linestyles
• Macros

On the whole, this actually involved less work than initially imagined, but as expected, there were certain issues that emerged during this process.

Interfaces

The custom Whitby Bird pull-down menus have been designed to remove the complication of drawing to the requirements of the company’s CAD standards by setting the active level, colour, style and weight for the CAD user. In v8 all levels have a default colour, line weight, and line style, and when elements are placed, they can either adopt the level’s colour, style and weight (known as “ByLevel”), or they can have their own unique symbology (the standard method in v7). The advantage that this new method offers is two-fold. If the symbology of all elements on a level is required to alter, this can be achieved by simply changing the level’s defaults. It also provides far more fluid interchange with the dwg “ByLayer” definition, which is commonly requested by recipients of dwg files.

The language behind MicroStation’s interfaces has not noticeably altered in v8, and so little modification was required to make the Whitby Bird pull-down menus work. A little re-writing was required to set the colour, weight and style assignments to “ByLevel”.

Seedfiles

The existing seedfiles required upgrading to v8 format. Any levels that were named in the v7 files were created automatically in the upgraded v8 version. We chose to delete these levels, with the intention of implementing a new system using Dgnlibs to define standard levels (this will be explained in detail later).

Cell Libraries

The standard Whitby Bird cell libraries required upgrading to the new v8 format. This format differs from the old one in that it is actually a dgn file containing a model of each cell, which can be opened and modified directly in MicroStation. This change of format caused us a problem with the level translation. In the old library, the cells were created on numbered levels 1 - 63, which when translated to v8 format, were named “Level1”, “Level2” etc.. instead of the BS1192 names that we use in our drawings. Once we’d upgraded the libraries, the only way to resolve this seemed to be to open the cell libraries and rename the levels. We subsequently discovered that this whole problem could have been avoided by using the MicroStation configuration variable MS_V7TOV8_CSVNAME, which when set to point to a Comma Separated Value file, can be used to automatically rename the levels during translation. 

Custom Linestyles

No modification or further development was required.

Macros

With the file format changes in V8, there was potentially a knock-on effect with any programming languages that interface with MicroStation directly. While MicroStation Basic Extensions (MBE) were still supported, the existing macros had to be extensively tested to make sure that all commands still achieved their desired intent. If the existing macros would not run, it would be necessary to re-write the macros from scratch in Visual Basic for Applications (VBA), now included with MicroStation V8. Only minimal modification of the existing MBE code was necessary, so the lengthy process of moving all macros to VBA has been postponed. The longer-term plan is to use VBA for all CAD macros, maintaining a more comprehensive suite of utilities in a standard language which can interface easily and directly with other Windows applications.

There are still a few minor changes pending, but this is not due to anything other than the change in our working methods made possible by the increased flexibility of MicroStation V8. Currently, the automated "New File" (creating new files in the correct directory from the correct seed) and "Place Title Sheet" (automatically attaching and filling in a drawing border) macros will need to be revised to suit the use of sheet models.

In parallel to testing and upgrading the existing Whitby Bird standards, we felt it necessary to investigate and evaluate the functionality and possible benefits of the new features of v8. Our findings were as follows:

Design History

This utility provides a complete version control system, which allows users to track and view the incremental changes made to a model. To help track these versions, each is identified with a revision number, the time and date, the author, and a description. This records the difference between the current state of the model and the last version saved, providing a persistent unlimited undo function. Once started, the Design History of a file cannot be removed, and similarly, there is no way to modify historical information.

Design History could prove to be an invaluable tool in the design process of Whitby Bird if used with respect. The concept of using Design History was put to the Structural CAD User Group (SCUG) for comment, who responded with reservations about the feature not being used correctly. Their concern is that for the system to work to our advantage, the description field of all revisions would have to be completed outlining the changes made. If this were not done consistently, it would prove extremely difficult to track revisions when a drawing was due to be issued. It would, however seem imprudent to dismiss the implementation of such a system on the merits that CAD users might not use the system correctly, when it could streamline the whole issue process considerably. It was also raised as a point of concern that as Design History is permanently stored within the file, when issued a file would retain all of our undisclosed design development revisions, which wouldn’t normally be made available. 

In order to make a fair assessment of the advantages and disadvantages of using Design History, it has been agreed that Design History will be used on a live test project to ascertain whether there is added value in using it. Only then will it be adopted as standard practice within Whitby Bird.

Dgnlibs

In MicroStation V8, the number of levels in a file is unlimited (previously restricted to 63). The user can delete unused levels and create new levels as and when required. All levels are named and have a default colour, line weight, and line style. 

Having spent considerable time standardising the Whitby Bird level naming and usage, we were initially concerned that all our hard work would be wasted as soon as users were given the ability to create levels how and when they liked. In investigating how v8 could be controlled to prevent creation of non-compliant or unnecessary levels, we discovered the means for doing so was by using a Dgnlib. This is simply a library of the standard Whitby Bird level definitions, which when attached to a blank dgn file would automatically provide the user with all the levels they require (hence the reason for deleting all levels in the seedfile). Any unused levels would remain visible until the file is issued externally, when only those used would appear. Levels within the Dgnlib cannot be deleted from a file. All Whitby Bird v8 CAD files will be produced using dgnlibs for defining levels.

Dgnlibs will also be used for defining Text and Dimension Styles. These are simply a saved set of dimension or text settings that the user selects when they wish to annotate a drawing. Text and dimension settings had been previously standardised at Whitby Bird, but we had to use the seedfile and a macro to set these. We have now decided to supply two separate Dgnlibs: one containing the standard Whitby Bird text styles and the other containing the standard dimension styles. These will still be selected using a macro, and users will not notice a change.

Create Package Wizard

Used to package up an environment from a user on one system for the benefit of another user on another system - potentially from another company. In operation, the Packager gathers all files related to a particular master design file (i.e. reference files, workspace settings, seedfiles and linestyle settings). These files are then analysed and the Packager reproduces the same file system structure as the source, based on the category of the files. 

Internal development of a similar utility has been done in the past, and it was hoped that Packager could be used by Whitby Bird for issuing digital CAD files. Its advantage is that the Packager automatically includes dependant files attached to the active file(s) being issued, and in theory offers the flexibility to be selective as to what is/isn’t issued. However, when testing this we found that the software actually included in the finished package workspace files we’d specified not to include. This could have serious consequences if a batch of information containing unintended files were issued externally. For this reason, we will not encourage users in Whitby Bird to use the Packager utility for issuing digital CAD files.

Models

When you draw, or place elements in a MicroStation DGN file, you are creating a model, which is stored as a discrete object within the DGN file. In MicroStation/J, we were restricted to one model per file, and so we structured our work on a file-by-file basis. The change in file format in v8 has brought about the ability to have multiple models in a file, which opens us up to endless possibilities. To assess the usability of this, we had to consider whether multiple models would have an advantage over the existing system. The system that is currently in place still fits our requirements without having any strong disadvantages; that is it allows a multi-user environment, ease of tracking information, and minimum re-working of modified information. The multi-model environment could actually cause us problems far outweighing the advantages, in that it would be more difficult to track information and it could actually restrict the maximum number of users on a project. 

One of the intentions of introducing the multiple model environment to MicroStation was actually to provide seamless exchange between v8 and AutoCAD, which raises another question - do we want our MicroStation drawings to translate seamlessly into AutoCAD? This question was put to the SCUG, who responded with mixed emotions. For translation to produce the correct results in AutoCAD, we would have to create more than one model in our drawing files. However, this would involve a complicated process which is very different to the current one, therefore requiring the CAD users to learn new procedures which would also take longer. The final decision was made to use this new process which still entails creating a separate “drawing” file and referencing in all relevant models, but has an additional step of self-referencing the model within the sheet model (or drawing file). When translated to dwg format, this produces a drawing with a title sheet in paper space and the external references externally attached in model space, with a paper space viewport scaled accordingly.

True Scaling

MicroStation v8 now recognises “real-life” drawing units and also how they relate to each other (i.e. 10mm = 1 cm, 25.4mm = 1 inch). Previous versions did not have this capability, and this led us into problems when units had to be changed partway through a project. With this new function, it is now possible to change the units of a drawing without having to scale the elements afterwards, or even attach reference files of different units to the master file without having to make any alterations, providing significant efficiency gains.

MicroStation v8 Collaboration Project

The sterile environment in which we’ve carried out initial investigations has only highlighted the technical advantages and disadvantages of upgrading. The only real way to progress from this position is to test the software in a real-life scenario, on a live project before rolling-out to the whole company. Simultaneously, we were intending to build relations with a like-minded architect, Sheppard Robson, who were also strategising their v8 upgrade, and to develop an awareness and understanding of each other’s systems for future work.

The Collaboration Project will be Paddington Central, which was chosen for the reasons outlined below:

• Large multi-discipline design team
• Mixed CAD software environment
• Inconsistent CAD standards
• Dwg-based co-ordinating architect

Initially, the project was started in v7, which was unfortunately unable to process the poorly-structured dwg formatted files that were being issued to Sheppard Robson and ourselves. Our project team approached us regarding the possible use of v8 to overcome this problem.

Before proceeding with the upgrade, we had to guarantee that v8 would not cause any detrimental effects to the project and any deadlines to which we were committed. Concerns were raised regarding the size of the project and its high profile nature. We were confident after our investigations that if used in the same manner as v7, there would be no noticeable downturn in productivity, in fact we were demonstrating the likelihood that it would be more efficient. We felt that the size of the project was not a major consideration, as its geometry and design is not too complex or unusual. The senior technician on the project is one of the most experienced MicroStation users in the company, providing additional security that in the event of unforeseen circumstances, no “cut-and-run” or reversion to v7 would be necessary.

Over the duration of this project, we hope to assess the impact and gain experience of the following, with the final outcome determining how the upgrade is rolled-out practice-wide:

Training

• Do we need to provide upgrade training at all?
• If so, what are the objectives and how do we go about achieving a cost effective solution? 

Dgnlibs

• · What are the practical advantages of using Dgnlibs?
•  Do they provide us with more flexibility and control when managing CAD Standards?

Interoperability with dwg

•  Is MicroStation v8 truly compatible with AutoCAD?
•  What benefits does v8 give to a project using dwg format and what problems are yet to be solved?

Design History

• Do the benefits of Design History outweigh the disadvantage of additional user effort required to input the necessary information?
• How can the information stored by Design History be utilised to aid cost management and audit trails? 

Sheet Models 

• Does the “dwg-style“ use of sheet models compare favourably against the traditional reference file methods of creating drawings? 
• Are there any effects on dwg compatibility? 
• What are the issues faced by the users in undertaking the new method of drawing compilation? 

AEC (UK) Level Standard

• Testing the proposed unified level standard. 

Methods of Data Exchange

• Providing information on preferred methods of data exchange. 
• What issues does the design team face? 

Project Structuring & data management

• Extracting advantages and disadvantages of the project’s setup including file naming, directory structures, configuration, backup and archive procedures. 

We intend to report on not only the management of v8, but also the usability and functionality. This will be achieved by holding regular meetings with the users to get their impressions and feedback on any issues or problems they have with the software.

The next part of this article will provide initial feedback from the project team. The final results and conclusions will be presented as part of the Bentley International User Conference 2002, held from May 19 - 23, in Atlantic City, New Jersey.