Book 28 — Information System Design
by The Editor
10. Quality Control of Rules and Regulation
The quality of a set of rules can be controlled only to the extent that it can be measured. SALADIN defines measures of quality and provides objective, constructive mechanisms for quality assurance. The results can therefore be accepted without acrimony and a harmonious partnership can be established between the people who draft the rules and the people whose responsibility it is to audit them.
SALADIN supports a process of continuous Quality Assurance by allowing work to be reviewed in small modules whose validity is easily checked. Thus corrective action can be initiated at low cost either by the reviewer or, if necessary, by an independent person or group. The costs of external assistance can be controlled by requiring that any independent Quality Assurance group cease its review as soon as two significant errors or sub-standard characteristics have been identified.
SALADIN provides a means of auditing not only the rules themselves but also the competence of the development organisation and the method being used; ideally, this should be SALADIN itself!
As well as checking the validity of existing rules, SALADIN can be used to write new sets of rules in such a way that they are proven to be logically complete and consistent at each stage as they are built up.
Because SALADIN can be used to define itself, it is possible to automate the translation of validated SALADIN specifications into working computer systems. The efficiency of the requirements specification process could be greatly enhanced by entering the draft rules for a test situation in a logical order into a computerised SALADIN workbench. As each component of the test situation is received, it is validated by the computer according to the pre-defined validation rules. If the validation rules are satisfied, the component is stored. By applying any further pre-defined rules, the practical consequences of the set of rules are derived and illustrated by computer animation. A printout of the results is provided as an audit trail for the user to study and confirm.
If the results are unsatisfactory, the rules can be modified and the whole process repeated as often as necessary to provide a set of rules which is not only logically complete and consistent but also produces satisfactory results in practice.
Because SALADIN specifications are provably complete and consistent, systems built strictly to these specifications are highly resistant to any form of corruption and can be made impregnable by unauthorised persons.
SALADIN identifies logical contradictions at the analysis stage. Snags are highlighted early, and the design takes them into account. For that reason, SALADIN is not a comfortable system to use: it imposes strict discipline on all concerned with a project. This may come as something of a culture shock to some participants and it may require courage and resolution on the part of the Client and members of the Client's organisation. But, strictly applied, SALADIN does result in the construction of effective systems installed on time and within budget.
If it is accepted that only one person or department can have the ultimate responsibility for ensuring the accuracy and validity of every record in each SALADIN table, completion of the Responsibility/Event section of the Table Definition reveals possible causes of internal friction if two or more potential rivals provide source material for the same table. If possible, each table or group of closely related tables should be controlled by only one clearly defined authority. The SALADIN analysis thus provides a sound framework for logical re-organisation.
SALADIN as described herein may be used freely by anybody. However, it will be found that whereas the charts and table definitions are easily understood once they have been produced, the initial compilation of a really useful set of charts and table definitions calls for a rather rare blend of skills.
The SALADIN practitioner must, of course, be a good analyst who can quickly grasp the essentials of any requirement. But not every good analyst is also a good system designer; and although the method ensures that every design is complete and consistent, there is no guarantee that it is also cost-effective. Elegant cost-effective design calls for a degree of creative talent and objective ruthlessness that may not always be readily available.
It may therefore be desirable to employ one or more consultants experienced in the application of SALADIN to oversee projects in which it is used. The degree of oversight provided may range from full Project Management down to vetting and quality control of SALADIN documentation produced by the Client's own staff.
SALADIN:
- is easily understood by the "owner" or user at any level in the organisational hierarchy.
- ensures problem analysis and definition are demonstrably complete and consistent.
- identifies problem areas whether of a technical, organisational, or "political" nature.
- facilitates accurate costing, thus increasing the likelihood that any project will run to time and keep within budget.
- if applied throughout the organisation, ensures uniformity of approach and resists "empire-building".
- is compatible with any techniques, methodologies, or systems which may already be in place.