IV EXISTING INTEGRATED SYTEMS 
Consideration of existing systems concerns their assessment, upgrading 
and further integration. Thus they emphasise operational research. The 
common items are the system components and their optimization, perfor- 
mance, reliability, cost, human factors, and support. 
1. The existing components (hardware, software, data base, etc) and their 
interactions can be upgraded and expanded. 
2. Performance pertains to operating (time) cycles and thus to production 
rates, and to product quality. 
3. Reliability affects the operation (down time), support, and the 
products (gross errors). 
4. Costs can be differentiated, e.g. according to initial investment, 
production and support. 
5. Human factors are involved in operation and in support. 
Ease of operation should be considered for hardware and operations 
involved in all production lines, including quality control. 
6. Support concerns all system components; it addresses check-out, test- 
ing and calibration, replacement of parts, upgrading system, training, 
instruction manual, etc. 
V PERFORMANCE AND RELIABILITY 
Performance and reliabity studies concern the methods, means and espe- 
cially the models for quality assessment. Quality pertains to both the 
products (information and data) and the production processes. It covers 
accuracy, fidelity, integrity, production rates, failability, etc. 
The methods can be differentiated according to analytical studies, 
simulation and experimental tests. 
Analyatical studies concern error propagation, information transfer, 
reliability analyses, time responses, etc. 
Simulation studies can be applied to hardware components and/or proce- 
dures. In the latter, the subject can be individual operations, 
production lines, or a project as a whole. 
Experimental tests can be differentiated similarly, i.e., according to 
hardware and procedures. Moreover, they can be integral (overall) or par- 
tial (component) tests, stationary or dynamic, using artifical or real 
input. 
  
VI EVALUATION 
Evaluation, in contrast to performance and reliability, concerns priority 
ranking of alternative systems (or sub-systems); performance and 
reliability considerations are part of it. For evaluation, is essential 
to identify the factors influencing system value, i.e., to formulate the 
value model, and subsequently to use a suitable valuation method. 
Occasionally, simple comparative evaluation of the alternative systems 
may suffice. 
Factors (or criteria) influencing system value can be differentiated ac- 
cording to desirability and feasibility. Each of these main categories 
can be further subdivided into overall and specific sections. 
Desirability factors affect policy making; hence they comprise social, 
economic and technologic criteria. Similarly, feasibility factors com- 
prise technical, human engineering and cost criteria. 
467