System Design

In a lot of ways, the design of your SGML system will parallel the design of your SGML document architectures. Just as you must consider your existing documents when designing your SGML document models, you must consider your current system as you plan your target system.

There is quite a bit of variance in SGML capabilities among the current generation of word processing and technical publishing systems. Although your current authoring program might offer SGML authoring features, you must ensure that the features offered fit your needs.

In many cases, organizations that want to make the transition to SGML authoring plan to use upgraded or enhanced versions of their current authoring package. However, upon examination of the specific SGML features offered in the enhancement, it is determined that the SGML support offered is not sufficient to their needs. In other cases, the current authoring package might offer no SGML support at all.

Thus, you are often at a crossroad as you plan your entry into the world of SGML. The question will arise, “Should I make the jump to a completely new authoring system to gain my SGML capabilities?” If this approach is the practical way to go, great. However, it often is a process that cannot be rushed, due to considerations relating to legacy data, staff training, investment in current systems, and so on.

When this is the case, you should consider the possibility of migrating to a “Transition” environment to bridge the gap between old and new (see fig. 23.3).

Fig. 23.3  Common steps in an SGML transition environment.

The transition environment can take a number of forms, depending on your needs. Commonly, it can include authoring in your current environment with a subsequent step of running conversion processing programs to convert the output documents into SGML.

Because the conversion processing is highly dependent on your document data formats, data structures, and related issues, it cannot be covered in detail here.

---

Tip:  
Perl, a text processing language, can be a very useful tool for performing SGML document conversion processing. It is examined in Chapter 28, “Other Tools and Environments.” Perl is also included on the SGML CD-ROM. Instructions for installing it are included in Appendix A.

---

---

• See “The World of Perl,” p. 491

• See “Perl,” p. 559

---

From Here…

This concludes your look at development and prototyping. As you examined the issues involved, you saw the important roles played by the definition of goals, team building, data gathering, and planning the transition from old to new systems.

For more information, refer to the following:

•  Chapter 24, “Understanding and Using Output Specifications,” examines issues relating to stylesheets and output specifications.

•  Part VII, “SGML Tools and Their Uses,” examines a variety of useful tools now available to help you use SGML.

•  Part VIII, “Becoming an Electronic Publisher,” examines the issues involved in moving into electronic publishing.