4GL's - Development software

Selection

Overview | Marketing/support | Language | Implementation | Features | Limitations

Overview

Since there are many varieties of 4gls available, and just as many opinions as which 4GL is "right", selecting a 4GL can be a minefield itself.

Judith Hurwitz suggests the following steps to select the "right" 3GL or 4GL

Assemble a team including both business analysts and developers
Look at the problem from a business perspective first
Base your choice of development language and tools on business benefits
Don't be influenced by the technical aspirations or resistance of programmers
Avoid relying on myths about abstracted languages.

[Ref 89]Computerworld NZ (Mar 1995)

Marketing and support

Supplier (hardware manufacturer, third party)
Number of installations (World Wide, Local)
Cost (NB. many are discounted when supplied by hardware manufacturers)
Host Systems
First Released (In user sites rather than beta test sites)
Main Support Centre
Local Support (By branch of company, or third party)

Language characteristics

Non-procedural(WHAT rather than HOW a specific task is to be performed)
Major User (end user, DP Professional or both)
Addresses all stages of the systems development cycle
Provides data integrity and security (100% commitment of transaction, or rollback if only partially completed)
Covers full program definition (creation of all programs without resorting to other languages, subsystems or utilities)
Menu selection
Online commands
Dialogue session
Online development

Implementation

DBMS (Manufacturer specific or commonly used)
Transaction Processing System

Data entry
Validation
Table look ups
Transaction logging

Data Dictionary
Graphics
Word Processing
Immediate execution (Interpreter available )
Compilation (compiler available to optimise programs)
Interface to other data
Interface to 3GL software

Features

Addresses and business application
(eg. COBOL type coverage?, decision support, statistical analysis)
Mainly reporting tool. (does it allow for data entry?)
Supports batch work

Limitations

Database
Files
Records
Concurrent users (i.e. number of users with updating facilities)
Processors (are distributed applications supported)

[Rev 27/6/97] © 1997 V/2-Com (Verhaart), P O Box 8415, Havelock North, New Zealand.