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lecture 1 : introductionThis lecture tries to answer the following questions:

•how different is IE from other engineering disciplines and from management?

•what is the relationship between IE, OR and MANAGEMENT SCIENCE ?

•what is IE work about?•who needs SYSTEMS THINKING and why?

•what is SYSTEMS THINKING anyway?

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what is IE work about?• IE seeks to improve organised human activity• organised human activity takes place in what we

can perceive as organisations or human activity systems

• human activity systems are social systems in the first place

• all engineering work has a social context, but systems that non-IE engineers work with are mostly perceived as technical systems

• technical systems are embedded in almost all human activity systems

• for this reason, human activity systems can also be called socio-technical systems

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how different is IE ?• engineers are concerned with goal seeking

systems that are primarily closed• this means that there is a goal the system

wants to achieve• such systems can be put into a laboratory

and studied in isolation from the environment

• the system can thus be reduced to its parts and analysed

• analysis can provide knowledge and understanding of a closed system

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• IE is concerned with purposeful systems that are always open

• a purposeful system is an organisation with goal seeking individuals

• these goals can change from person to person and also from time to time

• open systems do not fit into laboratories

• understanding an open system will not be possible through analysis only

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• analysis of a system reveals its structure and how it works; its product is knowledge, not understanding

• we need systems thinking to understand human activity systems

• systems thinking includes and complements analysis

• this is how OR/IE is different from most engineering and from “disciplinary” science

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IE – OR – MS • OR provides the “scientific” basis of IE• the mathematical models and

techniques used by IE are primarily OR models and techniques

• in the past, IE was more concerned with the engineering applications of OR

• IE now deals with almost all applications of OR, alongside traditional engineering

• MS is another term for OR

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who needs systems thinking ?As we already said before, IE learning

has dual objectives:• mastering quantitative analysis

and mathematical modelling (OR, probability theory, statistics, economics etc)

• building systems thinking skills in order to put this knowledge into effective use

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what is systems thinking ?five real-life examples that need ST:1. an emergency services call centre• answering, recording and checking

calls• providing fast response• balancing costs and waiting times• difficulty in evaluating response rate a queueing, or waiting line problem

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2. vehicle scheduling• varying pick-up/delivery times• “time-windows”• labour rules• capacity and congestion

restrictions• 20! = 2 432 902 000 000 000

000least time, least distance, least

cost ?

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3. writing a mission statement• should be relevant and

meaningful• achievable and measurable

goals and targets• active cooperation and

participation must be secured• often a compromise• lengthy canvassing and

negotiations neededsoft OR; problem structuring

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4. the “Deep Cove” project• an environmentally responsible economic

project to transport tail race water• no permanent residence in the sound,

reduced tanker speed, rubbish removal etc.

• but there will be other ecological risks:− increased salination− faster mixing of fresh and salt water− risk of spills− risk of introducing pests and poaching− etc.

conflicting objectives, MCDM

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5. screening for breast cancer• early tretment of growths • incidence rises with age• 95% chance of cure if detected at

preinvasive phase• mammography effective 85% of the

time• costs $200 000-$300 000 per machine;

$50-$100 per screening etc.what is the best screening policy ?how do we balance costs and human

suffering ?

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common features of these situations:– a complex problem situation

• what is the problem? • what do we mean by a solution?

– incomplete information– situation conceived as a system;

meaning that a system is,• not an ontological entity (ontology is an

area of metaphysics that studies the nature and existence of reality)

• but it is an epistemological entity (epistemology is an area of metaphysics that studies the nature of knowledge about reality)

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– situation requires systems thinking such as:•hard OR, or•soft OR

– all these situations involve gaining knowledge about a human activity system and all such knowledge is heavily meaning loaded and experience based

– knowledge is gained in what Checkland (1) calls the experience – action cycle:

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“systems thinking is to formulate some systems relevant to aspects of perceived reality that is of interest and then to use the systems in a methodology to find out about, or gain insight to, or engineer some of the world outside”the following figure from Checkland (1) summarises the difference between the two perspectives:

------------------------------------------------------------------(1) Checkland P.,J. Scoles Soft Systems Methodology in Action, Wiley 1990

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