LECTURE 28. Course: “Design of Systems: Structural Approach”

Dept. “Communication Networks &Systems”, Faculty of Radioengineering & Cybernetics

Moscow Institute of Physics and Technology (University)

Email: mslevin@acm.org / mslevin@iitp.ru

Mark Sh. Levin Inst. for Information Transmission Problems, RAS

Nov. 19, 2004

PLAN:

1.Preliminaries: life cycle, systems, utilization, personnel, maintenance, roles

2.Framework of maintenance process:

*basic framework, *systems under maintenance

*maintenance operations (inspection as testing/analysis/diagnosis, repair, *replacement)

*etc.

3.Illustrations: basic analogue (monitoring system), trajectory of fault.

1.Preliminaries

R & Dt

Manufacturing Testing MarketingUtilization &Maintenance Recycling

0 TNOW: HERE

SYSTEM

PERSONNEL

1.Preliminaries

R & Dt

Manufacturing Testing MarketingUtilization &Maintenance Recycling

0 TNOW: HERE

SYSTEM

UTILIZATION(e.g., driver, pilot, operator)

MAINTENANCE(support of system & personnel)

MAINTENANCE ACTIONS:

*system installation

*training of personnel*regular testing of personnel

*planning / scheduling of maintenance operations*execution of operations (inspection, repair, replacement)*analysis of the system, accumulation of data,prediction

1.Preliminaries

EXAMPLES:

SYSTEM UTILIZATION MAINTENANCE 1.Car Driver, passengers Maintenance personnel

2.Airlane Pilot, passengers Maintenance personnel

3.Human Human Doctor, human

4.House Owner Maintenance personnel, owner

5.Computer User(s) Maintenance personnel, special software, user(s)

2.Framework

TYPICAL FAILURE RATE CURVE:

Failurerate

TimeUseful periodInfant

mortalityWear outperiod

2.Framework

AN ORDINAL SCALE FOR FAULTS:

1.OK

2.Small fault

3.Significant fault

4.Damage (destriction)

2.Framework

OBJECT UNDER MAINTENANCE:

1.System and / or system part (component, unit)

2.System state

3.System function or function cluster (as a group of interrelated functions)

2.Framework

MAINTENANCE FRAMEWORK (problems):

1.System analysis / evaluation (systems, its part, etc.)2.System prediction3.Operational management / preventive maintenance: *testing *evaluation *additional information *repair / replacement4.Design of information model for system and each part (object)5.System strategy: *selection of object under maintenance *selection of operation (i.e., inspection, repair, replacement) *assignment of time for operation(s) *execution of the operation(s)

2.Framework

SYSTEM

Planning

Models for

system,faults,

prediction Maintenance operations

(scanning, repair, replacement)

MODELS:*selection, *knapsack, *routing, *assignment / allocation, etc.

*probabilistic models, Markov processes*reliability evaluation / analysis

*safety analysis*simulation

*etc.

Analysis,accumulation,

processing,integration

(fusion),distribution

ofinformation

2.Framework

SYSTEMS UNDER MAINTENANCE:

1.Whole system2.Multi-component (modular) system: *one-layer modular system *hierarchical (multi-layer) system *multi-layer modular system with complex module interrelation (including interrelation between different layers and branches)3.Developping systems (e.g., upgrade of components, structure, interconnection)4.Change of external environment

2.Framework

KINDS OF MAINTENANCE:

1.BASIC MAINTENANCE: faults => operation

2.PREVENTIVE MAINTENANCE: prediction of faults => preliminary maintenance operation 3.SELF-MAINTENANCE

2.Framework

SYSTEM CHARACTERISTICS:

1.Reliability (stability, etc.)

2.Safety

3.Viability, survivability

4.Robustness

4.Performance

2.Framework

PROBLEMS & MODELS OF PREVENTIVE MAINTENANCE:

1.REVELATION (ALLOCATION) OF TEST POINTSModels: multicriteria selection, knapsack-like problems, allocation problems, etc.

2.PLANNING TEST OPERATIONSModels: multicriteria selection, knapsack-like problems,scheduling, etc.

2.Framework

MODELING & INFORMATION PROCESSING:

1.Modeling of faults

2.Diagnosis of faults

3.Monitoring of faults

4.Tracking of faults

5.Integration (fusion) of information on local faults

6.Distribution of information on faults for various information systems and specialists

2.Framework

BASIC ACTIONS

1.Scanning

2.Small repair / replacement

3.Essencial repair / replacement

SYSTEM LAYERS

1.System2.System parts (group of states, group of functions)3.Components (state, function)

SYSTEM

3.Basic analogue: Monitoring systems

R

ControlIntegration

(fusion),analysis

SENSORS

ACTUATORS

Illustration: Accumulation of information

Normal situation

T0

Small fault

Mediumfault

Trajectory of faults (for components)

SYSTEM

System component

Small fault

FAULT/DAMAGE