SOFTWARE COMPLEX FOR AUTOMATED STRUCTURAL LOGIC
SIMULATING AND COMPUTING OF SYSTEM RELIABILITY AND SAFETY
(SC ASLS SZMA, version 1.0)
Process control system reliability is an important feature of the system quality
and an industrial site safety procurement requirement. Control system reliability
and safety assassment are required by State and international standards and regulations.
Hence control system designing and/or the operating Company’s readiness to provide
system reliability and safety analysis is a requirement for the Company’s certification
by State and International authorities. The main objective is to get consistent and
accurate information required for managerial decision making and support.
In 2002, the base version of the general-purpose Software Complex for automated
structural logic simulating and computing of reliability and safety measures of
control systems (SC ASLS SZMA) was developed by SPIK SZMA to support the design
process and to perform reliability & safety analysis of the large-scale, structurally
complicated Automated Process Control Systems (APCS).

The SC ASLS SZMA development environment: programming system Borland
Delphi Professional, Version 7.0. To run the software, the following operating systems
are required: MS Windows 98/ME, Windows NT/2000/XP. The SC ASLS SZMA’s basic sample is
used by SPIK SZMA’s project design department for reliability and safety assessment of control systems.
The SC ASLS SZMA’s theoretical base is a general logic probabilistic approach used
for the analysis of various structurally complicated objects and processes.
SPIK SZMA is interested in extension of the SC ASLS SZMA’s application experience and in
development of structural logical reliability and safety simulation & assessment technique.
The SC ASM SZMA application procedure consists of following three stages:
Task statement development:
- Development of the system’s functional integrity schema (FIS);
- Specification of logical criteria and conditions for the system’s main functions realization, emergency occurrences;
- Determination of probabilistic and other parameters of the system’s elements reliability and starting & initiation events;
- The initial data input (system architecture, parameters, criteria) into SC ASLS SZMA.
Automatic generation of logical and probabilistic mathematical models and computing of the system’s reliability and safety measures.
Computing is performed for each given function and failure.
User-friendly visualization of automated modeling and computing results for:
- System architecture versions analysis, comparison and selection;
- System’s reliability and safety decision making;
- Reporting documentation development.
The SC ASLS SZMA Main Window:

The Software’s Main window includes the following four segments:
1. Main box, located in the upper part of the SW ASLS’s Main window and containing control
elements for all SW ASLS functions realization, consists of four bars:
- Title bar;
- Main Menu bar;
- Two control element toolbars.
2. The system’s FIS Input box;
3. Box for elements’ parameters input and automated simulation mode setting;
4. Simulation and computing results output box.
SC ASLS SZMA characteristics:
Unlike other simulation software packages
(Risk Spectrum, SAPHIRE, RiskWave, RISK Project, RAY, CRISS, etc.), SC ASLS SZMA is
first to support all capabilities of Boolean algebra simulating in the operational
basis AND, OR, NOT. It therefore, can perform almost all logic probabilistic simulating
tasks and, moreover, a new class of non-monotonous analysis tasks applied to complex
objects & processes reliability and safety;
SC ASLS SZMA automatically determines the list of shortest paths of the successful
functionality, minimal cuts of failures and their combinations;
SC ASLS SZMA applies an advanced
graphical tool for system’s architecture description – functional integrity
scheme (FIS). Using FIS all systems can be represented by means of one of the
typical system’s architecture descriptions – functional scheme, elements’
series-parallel connections, failure trees, event trees, connectivity graphs, etc;
While developing the FIS,
one can use either direct (system’s capacity, safety, efficiency)
or reverse (system’s failure, emergency, risk) logic of reasoning and justification;
SC ASLS SZMA’s graphical interface
realizes the principle of two-level decomposition (equalization, aggregation),
i.e. system FIS graph can include up to several hundred nodes and each of them,
in its turn, can contain up to one hundred element graphs of the second level;
SC ASLS SZMA automatically generates
system’s reliability and safety mathematical models as exact (or - in case
of working memory shortage – approximate) polynomials of computing probabilistic functions;
Based on computed polynomials SC ASLS SZMA performs
computing of the following reliability and safety parameters for each main function and each failure:
-probability of a non-restorable system’s non-failure operation;
-MTTF;
-availability function of a restorable system;
-mean time of the system restoration;
-probability of a restorable system’s non-failure operation;
-probability of the failure occurrence;
-significances and contributions of separate elements into the whole system reliability and safety measures;
-computing results are displayed by tables and graphs and are saved in the data base as well;
SC ASLS SZMA can be adapted to application in new
object domains which may affect the list of parameters being computed;
Stochastic dependences among elements,
multiple (more than two) working and failure states, multifunctional elements, failure due to a
common cause, system capability to function in various states with different effectiveness and
safety degree can be considered in developed models.
SC ASLS SZMA is currently used by SPIK SZMA’s project design department with the following application experience:
Implementation of reliability assessment for SPIK SZMA’s control system projects:
- Pumping Station 910-45 and associated reservoirs.
- Gas Fractionating Plant.
- Crude oil tank farm fire-fighting systems.
- LPG Plant Tank Farm, extension.
- LG24/7 Flow #1 Retrofit implementation of the process control system and field instrumentation.
- Air compressors control system.
- Emergency shutdown system for the section 400 of the Plant LK-6UNo1.
- Emergency shutdown system for the section 100 of the Plant LK-6UNo1.
- Oil, Fuel Oil and Vacuum Gas Oil Discharge Station.
Associated with SC ASLS SZMA were developed an Enterprise Standard ‘Reliability computing for designed
objects’ and a Work Instruction ‘Guidelines on reliability computing for designed objects’.
By order of Association ‘Montageautomatica’ (Moscow) SPIK SZMA
developed Methodological guidelines ‘Reliability and safety. Automated structural logic simulation and
computing of designed process control system safety and reliability. Methodological guidelines’.
The Methodology was approved by:
-Riabinin I.A., academician, founder of Russian logic probabilistic simulation school;
-Association ‘Montageautomatica’ (Moscow);
-Nuclear industry inspectorate (PROMATOMNADZOR) of Belarus Republic (Minsk, Belarus Republic);
-Central research and development institute for complex automation (CNIICA) (Moscow);
-NEFTECHIMINFORMATIKA (Moscow);
- Saint-Petersburg institute for informatics of the Russian Academy of Science (SPIIRAS) (Saint-Petersburg);
- Saint-Petersburg research and development and designing institute ATOMENERGOPROEKT.
The Methodological guidelines will be considered by the Research and Technical Committee of the RF Gosgortechnadzor.
Contact person for all technical issues: SPIK SZMA’s specialist Mozhaev Alexander.
Phone number: +7 (812) 350-5885.
E-mail: Alexander_Mozhaev@szma.com