of 56
7/28/2019 computers in management 1
1/56
VIGIN VARKEYS2 IEMVJCET
7/28/2019 computers in management 1
2/56
1. Hardware provides basic computing resources(CPU, I/O devices).
2. Operating system controls and coordinates the useof the hardware among the various applicationprograms for the various users.
3. Applications programs are used to solve thecomputing problems of the users ( business programs,
video games).4. Users (people, machines).
7/28/2019 computers in management 1
3/56
A program that acts as an intermediary between auser of a computer and the computer hardware.
Computer systems typically contain:Hardware and Software
7/28/2019 computers in management 1
4/56
Hardware - electronic, mechanical, opticaldevices
Software programs Without support software, the computer is of
little use.. when the computer is on, OS will first load
into the main memory Operating system goals:
Execute user programs and make solving userproblems easier.
Make the computer system convenient to use.
7/28/2019 computers in management 1
5/56
Operating
System
Device configuration
Controls peripheral devices connected to the computer
File management
Transfers files between main memory and secondarystorage, manages file folders, allocates the secondary
storage space, and provides file protection and
recovery
Memory management
Allocates the use of random access memory (RAM) torequesting processes
Interface platform
Allows the computer to run other applications
7/28/2019 computers in management 1
6/56
provide a background for users programsto execute
display and deal with errors when it
happens control the selection and operation of the
peripheral devices.
act as a communication link between userand hardware.
system protection
7/28/2019 computers in management 1
7/56
7/28/2019 computers in management 1
8/56
to handle 2 or more programs at the sametime from a single user s perception CPU can only perform one task at a time, however,
it runs so fast that 2 or more jobs seem to execute
at the same time
7/28/2019 computers in management 1
9/56
Through computer networking CPUshandles different jobs.
Job1
Job2
Job3
Job
4
Job1
Job2
Job3
Job4
CPU 1 CPU 2 CPU 1
time
time
without
multiprocessingwith multiprocessing
7/28/2019 computers in management 1
10/56
a temporary storage area (buffers) to readdata from input device or send data to theoutput device.
7/28/2019 computers in management 1
11/56
Spooling is the process of a sending data to atemporary storage area in the computer'smemory. This data may contain files orprocesses.
The most common type of spooling is printspooling, For example, when you print adocument from within an application, thedocument data is spooled to a temporary storagearea while the printer warms up. As soon as the
printer is ready to print the document, the data issent from the spool to the printer and thedocument is printed.
http://www.techterms.com/definition/memoryhttp://www.techterms.com/definition/filehttp://www.techterms.com/definition/processhttp://www.techterms.com/definition/processhttp://www.techterms.com/definition/filehttp://www.techterms.com/definition/processhttp://www.techterms.com/definition/applicationhttp://www.techterms.com/definition/applicationhttp://www.techterms.com/definition/applicationhttp://www.techterms.com/definition/processhttp://www.techterms.com/definition/filehttp://www.techterms.com/definition/memory7/28/2019 computers in management 1
12/56
7/28/2019 computers in management 1
13/56
Single User Operating System Multi-User Operating System
Multi-Tasking Operating System
Distributed Operating System Batch processing Operating System.
Real time processing Operating System.
7/28/2019 computers in management 1
14/56
As the name implies, Single-user-operatingsystem is designed to manage the computerso that one user can effectively do one thingat a time.
for example: DOS
7/28/2019 computers in management 1
15/56
Multi-user OS is that which support more thanone users at the same time. in these types of OSthere is a server and all the users are provideddifferent terminals. these terminals areconnected to the server.
A multi-user operating system differs from asingle-user system on a network in that eachuser is accessing the same OS at differentmachines.
for example, the OS may need to handle
numerous people attempting to use a singleprinter simultaneously. The system processes therequests and places the print jobs in a queuesequence.
7/28/2019 computers in management 1
16/56
A multitasking OS allows you to run multipletasks "simultaneously". They do not actually runat the same time, since there is only one CPU.
Usually CPU process only one task at a time but
the switching is so fast that it looks like CPU isexecuting multiple processes at a time.
the concept behind this is timesharing...operating system divides cpu timeamong various tasks but this time is very
small(nanosecond) that user feel that allprograms or tasks are runningsimultaneously......
7/28/2019 computers in management 1
17/56
This type of operating system is seeneverywhere today and is the most commontype of OS, the Windows operating systemwould be an example.
7/28/2019 computers in management 1
18/56
In a distributed system, software and datamaybe distributed around the system,programs and files maybe stored on differentstorage devices which are located in different
geographical locations and maybe accessedfrom different computer terminals.
This is not used in commonly.
7/28/2019 computers in management 1
19/56
Jobs, together with input data, are fed intothe system in a batch.
The jobs are then run one after another.
No job can be started until previous job iscompleted
7/28/2019 computers in management 1
20/56
Inputs immediately affect the outputs. Timingis critical e.g. Data from sensors is processed
immediately and provide outputs.(controlling of some nuclear power plants,chemical processing etc)
Timing is critical so the term refers Real timeprocessing Operating System anti-missile defense system
airplane landing control system
7/28/2019 computers in management 1
21/56
efficient time spent to execute its programs should be short
small in size memory occupied should be as small as possible
reliable
7/28/2019 computers in management 1
22/56
DESCRIPTION Simulation is a very powerful and widely used
management science technique for the
analysis and study of complex systems. This is normally done by developing a
simulation model. A simulation model usuallytakes the form of a set of assumptions about
the operation of the system, expressed asmathematical or logical relations between theobjects of interest in the system.
7/28/2019 computers in management 1
23/56
What is simulation:The process of designing a mathematical or
logical model of a real-system and thenconducting computer-based experimentswith the model to describe, explain, andpredict the behavior of the real system.
7/28/2019 computers in management 1
24/56
Simulation: Imitate the operations of afacility or process, usually via computer Whats being simulated is the system
To study system, often make
assumptions/approximations, both logical andmathematical, about how it works
These assumptions form a modelof the system
If model structure is simple enough, could use
mathematical methods to get exact information onquestions of interest analytical solution
K. Salah 24
7/28/2019 computers in management 1
25/56
But most complex systems require modelsthat are also complex (to be valid) Must be studied via simulation evaluate model
numerically and collect data to estimate model
characteristics Example:- Simulation Based Plant
Maintenance Planning
K. Salah 25
7/28/2019 computers in management 1
26/56
7/28/2019 computers in management 1
27/56
Some (not all) application areas Designing and analyzing manufacturing systems Evaluating military weapons systems Designing and operating transportation systems
such as airports, freeways, ports, and subways
Determining ordering policies for an inventorysystem Reengineering of business processes
{Fundamental changes to people and culture,organizational structure, policies/procedures,
and technology} Evaluating designs for service organizations suchas call centers, fast-food restaurants, hospitals,and post offices
K. Salah 27
7/28/2019 computers in management 1
28/56
Many a times, the first simulation study isconducted by an external consultant in partbecause in-house staff is not familiar with thetechnique, and the staff is busy with every
day tasks. Unrealistic expectations from management
may result in simulation modeling beingconsidered as an empty promise tool.
Here we discuss how these challengespresent themselves and how they can beaddressed.
7/28/2019 computers in management 1
29/56
7/28/2019 computers in management 1
30/56
Simulation Can: Measure Time in the system.
Measure Worker / machine utilization. Evaluate Changes to system inputs / resources
such as rate of arrival, rate of service.
Number of trucks available to move material fromone work station to another.
Simulation Cannot: It cannot give accurate results if the inputs are
inaccurate. It cannot solve problems; it can only provide
information from which solutions can beinferred.
7/28/2019 computers in management 1
31/56
Advantages of Simulation Simulation Methods are usually easier to apply thananalytic methods.
Once a model is built, it can be used repeatedly forvarious analyses.
Simulation data is usually cheaper than datacoming from the real system.
Disadvantages of Simulation Simulation models may be costly to build.
Because of its statistical nature, many runs ofthe same model are necessary to achievereliable data.
7/28/2019 computers in management 1
32/56
1.Total enterprise simulation These simulations involve modeling all or most
business functions (marketing, finance, operationsand R & D)
Its the first computerized business simulation. Total Enterprise simulations is divided into four
categories a)strategic management,b)business appreciationc)tactical management andd)totality simulations.
7/28/2019 computers in management 1
33/56
These simulations cover the strategic management of
business. They may be run in a single session, spread over a course or
run on a spare time basis over several months.
Decisions cover marketing, finance, operations and productdesign and development.
To constrain complexity (and so duration) the tacticaloperation of the business (scheduling, material supply,distribution, etc.) is often done automatically by thesimulation model and so few or no decisions are made inthese areas.
these simulations are most appropriate for middle to seniormanagement development.
7/28/2019 computers in management 1
34/56
These simulations are designed to show businesspeople how a business operates, develop business
acumen and basic financial knowledge.
Besides running as a single session, they can be
spread throughout a course, with one or moreperiods simulated each day.
These simulations are designed for junior tomiddle management, management trainees,
supervisors and functional specialists.
7/28/2019 computers in management 1
35/56
These simulations cover the tactical managementof a business.
In contrast with strategic simulations that focus onthe external environment, these concentrate on the
internal management of the business. The simulation model is usually complex,
especially concerning factory and financialmeasures of the efficient operation of the business.
7/28/2019 computers in management 1
36/56
It is used to describe those simulations thatattempt to replicate, in detail, the entire operationof a "real"business.
They combine the characteristics of strategy and
tactical simulations. complexity means that they take considerable time
to run and their scope may mean that they lack thefocus necessary for efficient use of learners time.
7/28/2019 computers in management 1
37/56
These simulations focus on a specific functionalarea (sales, marketing, operations etc.)
These simulations are complex and usually last aday or more. Multiple decisions are made each
period but, unlike most other simulations, theseare of differing level of importance.
some decisions are of strategic importance, someof tactical importance and some are operational
necessities.
7/28/2019 computers in management 1
38/56
These simulations focus on specific business issuesand concepts
These are short, two to four hour, simulationswhere groups of learners enter decisions into their
own computer, receive and analyse results. These are used to reinforce a topic, test
participants' understanding and provide a change
of pace.
7/28/2019 computers in management 1
39/56
These involve the preparation of a business planusing a "What-If" model
Planning simulations are of particular use wheremanagers need to understand the business
implications of the topic. Planning simulations can be at a Strategic, Tactical
or Operational Level. Strategic planning simulationsinvolve learners preparing a plan covering severalyears. Tactical planning simulations involvelearners preparing a plan for the next yearsoperation on, typically, a month-by-month.
7/28/2019 computers in management 1
40/56
These are simulations that involve the practical useof mathematical techniques such as statisticalforecasting, inventory planning, analysis of sales
performance etc.
A process simulation involves taking different setsof data through a business process to findpatterns, discuss implications and produce
forecasts or outcomes.
7/28/2019 computers in management 1
41/56
Introduction The use of simulation is as old as the practice of
engineering itself, what has been very useful is the useof the computer to assist one in the analysis of largecomplex engineering and scientific problems.
Lately the advent of special high level computersoftware packages has made the use of the computereven easier and has increased the productivity of thescientists and engineers that use these tools.
Many of these software tools were very specialized andapplied to a narrow subject field. They are quite useful,however, it is very difficult to apply them to anothersimilar area.
7/28/2019 computers in management 1
42/56
The latest development is the appearance ofseveral general purpose high level softwarepackages that are able to be applied to anyproblem of mathematical modeling that containsnon-linear, non-homogeneous, simultaneous,
high order, ordinary and parabolic partial,differential equations with associated algebraicequations and discontinuities.
Computer Simulation can be used to represent ingreat detail the performance of real world
systems which are often very complex (e.g. spacecraft, control systems, mechanical and electricalsystems, etc.).
7/28/2019 computers in management 1
43/56
High-level continuous systems simulationlanguages are application oriented softwaresystems designed to assist Engineers andScientist to mathematically model and
analyze the behavior of piecewise-continuoussystems described by differential equations.
7/28/2019 computers in management 1
44/56
Introduction 44
Assuming Simulation is the appropriate
means, three alternatives exist:
1. Build Model in a General Purpose
Language
2. Build Model in a General SimulationLanguage
3. Use a Special Purpose SimulationPackage
7/28/2019 computers in management 1
45/56
Introduction 45
Advantages: Little or no additional software cost
Universally available (portable)
No additional training (Everybody knows(language X) ! )
Disadvantages: Every model starts from scratch
Very little reusable code
Long development cycle for each model Difficult verification phase
7/28/2019 computers in management 1
46/56
Introduction 46
FORTRAN Probably more models than any other
language.PASCAL
Not as universal as FORTRANMODULA
Many improvements over PASCALADA
Department of Defense attempt at
standardizationC, C++ Object-oriented programming language
7/28/2019 computers in management 1
47/56
Introduction 47
GPSS Block-structured Language Interpretive Execution FORTRAN-based (Help blocks) World-view:Transactions/Facilities
SIMSCRIPT II.5 English-like Problem Description Language Compiled Programs Complete language (no other underlying
language) World-view:Processes/ Resources/
Continuous
7/28/2019 computers in management 1
48/56
Introduction 48
MODSIM III Modern Object-Oriented Language
Modularity Compiled Programs
Based on Modula2 (but compiles into C)
World-view:Processes
SIMULA ALGOL-based Problem Description Language
Compiled Programs World-view:Processes
7/28/2019 computers in management 1
49/56
Introduction 49
SLAM Block-structured Language
Interpretive Execution
FORTRAN-based (and extended)
World-view:Network / event / continuous
CSIM process-oriented language
C-based(C++ based) World-view:Processes
7/28/2019 computers in management 1
50/56
Introduction 50
Advantages Very quick development of complex models
Short learning cycle
No programming--minimal errors in usage
Disadvantages High cost of software
Limited scope of applicability
Limited flexibility (may not fit your specificapplication)
7/28/2019 computers in management 1
51/56
Introduction 51
NETWORK II.5 Simulator for computer systems
OPNET
Simulator for communication networks,including wireless networks
COMNET III Simulator for communications networks
SIMFACTORY Simulator for manufacturing operations
7/28/2019 computers in management 1
52/56
One of the great features of ESL is its ability tohandle discontinuities accurately. This was one ofthe European Space Agencies originalspecifications as when a thruster on a satellite isfired it must happen at the specified time and not
at the nearest integration interval. Examples of the use of ESL are the simulation ofa six legged robot combined with 3D animatedgraphics with a human controller in the loop andthe entire system running on multiple platformsin real time, as a training simulator for a processcontrol filtering system in a large water treatmentplant, and of course for satellite orbit analysis.
7/28/2019 computers in management 1
53/56
The European Space Agency Simulationlanguage (ESL) was originally written to meetthe simulation requirements of the EuropeanSpace Agency. It started out as a general
purpose Continuous Systems SimulationLanguage (CSSL) and can still be used for thatpurpose.
It has a comprehensive supporting softwareenvironment and it can be used in any fieldwhere dynamic systems are studied and theirsimulations need to be used.
7/28/2019 computers in management 1
54/56
CSSL-IV is a user-oriented software system designed tosupport analytical simulation. Availability, ease of use, andpowerful support tools allow CSSL-IV to be appliedeffectively to a broad range of technical problems.
Application areas range from aircraft flight dynamics,nuclear reactors, chemical processes, and physiological
dynamics to a wide variety of control systems. CSSL-IV provides access to many powerful programming
tools which speed simulation development andverification. Powerful systems-oriented functions coupledwith extensive man-machine inter-active capabilities allowthe user to concentrate on his/her simulation studies with
minimal burden from the computer system.
7/28/2019 computers in management 1
55/56
ACSL (pronounced "axle") is an AdvancedContinuous Simulation Language. It wasintroduced 25 years ago, as a commerciallyavailable, modeling and simulation language
designed for simulating continuous systems.Based on the CSSL (Continuous SystemSimulation Language) standard, establishedby the Technical Committee of the Society for
Modeling and Computer SimulationInternational, [SCS].
7/28/2019 computers in management 1
56/56
ACSL Sim was designed to help the engineer orscientist, mathematically model and analyze thebehavior of a continuous system described bytime-dependent, nonlinear differential equations
and/or transfer functions. Although continuous systems by their nature are
time-dependent, ACSL Sim lets you designate theindependent variable as something other than
time, such as distance or angle. This gives theuser the flexibility to model a multitude ofdynamic systems.