1 soft systems method an introduction methods for information systems development soft systems...

1

Soft Systems Method An Introduction

Methods for Information Systems Development

Soft Systems Ideas

Overview of Soft Systems Method

Rich Pictures

Relevant Systems and Root Definitions

Conceptual Modelling

Bringing About Change

2

Information Systems Methods

Structured Methods:

• Yourdon, SSADM, Information Engineering

Object Oriented Methods:

• OOSE, OMT, Rational (UML)

RAD Methods

• DSDM

‘Bottom Up’ Evolution: Programming, Design,

Analysis, . . . .

All Based On Sound ‘Engineering’ Principles:

• i.e. First Know Requirements then Build a System

3

Computer

Division

Problem Situation: Often ‘Out of Stock’ of Products Sold

Solution: Computerise Production Planning

Result: Company Closure

A Cautionary TaleManaging Director

Finance

Division

Sales

Administration

R & DMarketing

Division

Sales Division

Production

Division

Activities:1 Forecast Sales2 Buy Materials3 Manufacture4 Sell5 Deliver

4

Types Of System

DESIGNED PHYSICAL SYSTEMS, e.g. Bridge,

Aircraft, Channel Tunnel, Power Station

COMPONENT PARTS are Physical Components

HUMAN ACTIVITY SYSTEMS (HAS), e.g. An

Information System

COMPONENT PARTS are Physical Components

but also Humans Performing Tasks

IS Methods Are Based on Same Principles as

Building DESIGNED PHYSICAL SYSTEMS, But . .

5

An HAS is More Than A Set of Activities

SOCIAL SYSTEMPLUS

HUMAN ACTIVITY SYSTEM

SYSTEM OF

ACTIVITIESEQUALS

TRANSFORMATION PROCESS

(Modelled as an Interconnected Set

of Activities)

Input(s) Output(s)

Elements = Activities (or sub-systems), i.e. “WHAT”

Relationships = Logical Dependencies

Elements = People Doing Activities, i.e. “HOW”

Relationships = Inter-Personal

6

PROBLEM SITUATIONS

HARD May Be Analysed as a

‘Designed Physical System’ and Modelled

Mathematically

SOFTMay be Analysed As a Set of HASs

where Modelling Language Consists of

Activities (Verbs) but . . . Can We Ignore

Inter-Personal Relationships?

7

Aims of Soft Systems Method

SSM is NOT a Method for Developing an Information

System

SSM Aims to Bring About ‘Improvement in a Problem

Situation’

To Develop an Information System, Requirements Have

to Be Established and Agreed

SSM Could be Used to Help People ‘Agree on the

Requirements’

If Requirements are Unclear, SSM Could Be a Front End

for a DSDM (or Other Method) Development

But, It May (or Even More Likely) Result in Change that

Does Not Require the Building of an IS

8

Soft Systems Ideas PROBLEMS Do Not Have an Existence Independent of

the Humans Involved With Them

People Will See the Same Situation in Different Ways

"Filter"

WObservation OfReal World Events

9

Soft Systems Ideas PROBLEMS Do Not Have an Existence Independent of

the Humans Involved With Them

People Will See the Same Situation in Different Ways

If ‘Problems’ are Intellectual Constructs then so should

be ‘Solutions’

Problems do not exist in Isolation

Improvements in a Problem Situation Are Most Likely to

Come About Through Persuasion and Debate

The Analyst is a ‘Catalyst of Change’ and cannot be

divorced from the situation.

"Filter"

WObservation OfReal World Events

10

SOFT SYSTEMS METHOD

3. RELEVANT SYSTEMS AND ROOT DEFINITIONS

RS 1

RS 2

RS 3

RD 1

4. CONCEPTUAL MODEL

ABSTRACT

WORLD OF

SYSTEMS

THINKING

7. IMPLEMENT CHANGES

6. DEBATE ON FEASIBLE

AND DESIRABLE CHANGES

2. THE SITUATION ANALYSED

Rich Picture

Issue 1

Issue 2

Primary Task

REAL WORLD

1. THE PROBLEM

SITUATION UNSTRUCTURED

5. COMPARISON OF

4 WITH 2

11

ANOTHER VIEW OF SSMStep 2 - Look At The Complex Situation. Represent Its Complexity, Without Jumping to Conclusions About the ‘Type’ of Situation or the Nature of the Problem

Step 7 - Implement Agreed Changes

Step 4 - Build a Model of the ‘Relevant System’ (Issue or Task-based). What Will the System Logically Have to Do If It Were the System Defined

Step 6 - Discuss the Consequence and Agree Changes (Defined by Those Involved - NOT the Analyst)

REAL WORLD

Step 5 - Compare the Model With the Actual Situation

REAL WORLD

Step 3 - View the Situation in Terms of a ‘Relevant System’ (Issue or Task-based)ABSTRACT

WORLD OFSYSTEMSTHINKING

12

SSM - STAGE 1 ENQUIRY Begins With A ‘Mess’ OR ‘ A Setting Where Someone

Thinks a Problem May Exist

Resist Attempts to Impose a Particular Structure on the

Situation

Recognise That You Will Become Part of the Situation

Do Some Thinking About the Following Roles:

Make Practical and Administrative Arrangements,

E.G. Negotiate Access to People, Locations, …Arrange a

Quiet Office. Determine Method of Recording Information

From Interviews

The

Problem

Solver

The

Client

The

Problem

Owner

13

SSM - STAGE 2‘The Situation Analysed’

Conduct Interviews. Draw a Rich Picture

Guidelines:

Look for Elements of Structure of the Situation

Look for Elements of Process

Look for Interaction of Structure and Process

Do Not Try and Represent the Situation in Terms of

Systems.

Ensure Your Picture Includes ‘Hard’ Factual and ‘Soft’

Subjective Information

Look at Social Roles. Try and Identify ‘Good’, ‘Bad’, and

‘Acceptable’ Behaviour.

Annotate Picture With Footnotes

Include Yourself in the Picture

14

RICH PICTURE - SOAP ‘n’ SPRAY

15

RICH PICTURE - ALBION MILLS

Courtesy Open University

16

SOFT SYSTEMS METHOD

3. RELEVANT SYSTEMS AND ROOT DEFINITIONS

RS 1

RS 2

RS 3

RD 1

4. CONCEPTUAL MODEL

ABSTRACT

WORLD OF

SYSTEMS

THINKING

7. IMPLEMENT CHANGES

6. DEBATE ON FEASIBLE

AND DESIRABLE CHANGES

2. THE SITUATION ANALYSED

Rich Picture

Issue 1

Issue 2

Primary Task

REAL WORLD

1. THE PROBLEM

SITUATION UNSTRUCTURED

5. COMPARISON OF

4 WITH 2

17

SSM - STAGE 3 ‘Relevant Systems’

A Systemic Way of Viewing the Situation Which Is (in the

opinion of the analyst), in Some Way, Relevant to the

Problem Situation

When Described in More Detail It Is Hoped That Studying

the Abstract System Will Yield Insight Into the Situation

Relevant Systems May Be of Two Types:

Issue-based - Will Focus on Specific Issues and Seek to

Address or Act Upon Them in Some Way

Task-based - Are Attempts to Describe, or Capture, the

Essential Nature of a Fundamental Task Which Must Be

Carried by the Organisation Under Study

18

SSM - STAGE 3 ‘Root Definitions’

DEFINITION - A Precise Verbal Description of the Essence

of the Processes Implied by the RELEVANT SYSTEM

EXAMPLE “A SOAP’N’SPRAY Owned System Engaged in

the Manufacture and Supply of Soap Products to Satisfy

Customers’ Orders in a Way That Is Consistent With

Performance Levels Desired by Corporate Headquarters”

A Relevant System Is a ‘System’. Hence It Must Conform

to ‘Systems Theory’

It May Help to Consider a CATWOE Analysis

19

CATWOE Analysis of SOAP’N’SPRAYC- CUSTOMERS of the System

Those Who Order Soap Products (European, Retailing, Commercial and

Industrial Markets)

A - ACTORS

Those Who Carry Out the Manufacture and Supply Activities

T - TRANSFORMATION PROCESS

Transform Vegetable Oil (and Other RMs, If Needed) Into Finished

Soap Products and Supply to Customers

W - WELTANSCHAUUNG

A Concern to Meet Orders Whilst Achieving Financial Targets Set by

HQ

O - OWNERS

SOAP’N’SPRAY (Note: the owners of the relevant system, not the

business)

E - ENVIRONMENTAL CONSTRAINTS

The Business and Commercial Competitive Environment

20

SOFT SYSTEMS METHOD

3. RELEVANT SYSTEMS AND ROOT DEFINITIONS

RS 1

RS 2

RS 3

RD 1

4. CONCEPTUAL MODEL

ABSTRACT

WORLD OF

SYSTEMS

THINKING

7. IMPLEMENT CHANGES

6. DEBATE ON FEASIBLE

AND DESIRABLE CHANGES

2. THE SITUATION ANALYSED

Rich Picture

Issue 1

Issue 2

Primary Task

REAL WORLD

1. THE PROBLEM

SITUATION UNSTRUCTURED

5. COMPARISON OF

4 WITH 2

21

SSM - STAGE 4 ‘Conceptual Models’

A Model of the Activities or Processes That Logically

Ought To Go On If the Relevant System Is to Be the

One Described by the Root Definition

A1

A2A3

A4

A5

A6A7

A8

A10A9

A GENERALISED CONCEPTUAL MODEL

22

Conceptual Model - Guidelines

Activities are Represented by VERBS

Arrange into a Logically coherent Order

Aim for 6 to 12 Activities for a Complete Account

Examine Each Main Activity and Identify Subsidiary

Activities, Each Written Down As a Verb

Group Functionally Similar Activities into Sub-

Systems

Remember It Is a Logical Model - No Real-World

Considerations

If Necessary, Revise the Root Definition

23

SSM - STAGE 4 ‘Conceptual Model’

FRONT LINE ACTIVITIES:

RECEIVE Customer Orders for Soap Products

KNOW Performance Levels Required by HQ

MANUFACTURE Soap Products

OBTAIN Raw Materials

DISTRIBUTE Soap Products

PLAN Operations Needed to Meet Orders

MONITOR & CONTROL

All the Above Activities

"A SOAP'N'SPRAY - Owned System Engaged in the Manufacture and Supply of Soap Products to Satisfy Customers' Orders in a Way that is Consistent with the Performance Levels Desired by Corporate Headquarters."

24

Conceptual Model - SOAP ‘N’ SPRAY

KNOW HQ's

Requirements

PLAN Operations

RECEIVE Customer

Orders

MONITOR & CONTROL

All Activities

MANUFACTURE Soap

Products

OBTAIN Raw Materials

DISTRIBUTE Soap

Products

FIRST STAGE MODEL

25

Conceptual Model - SOAP ‘N’ SPRAY

RECEIVE Purch. Reqs

KNOW Buying Pol'y

DECIDE Where To

Obtain GoodsORDER Goods

INFORM Concerned

Groups

OBTAIN

RECEIVE Delivery Not'n

KNOW Facilities

ANALYSE Info Rec'd

RECEIVE Orders Info

DECIDE

ASSEMBLE Decisions

PLAN

TRANSMIT Info

SCHEDULE Activities

MAINTAIN Plant

MAKE Products

RECEIVE RMs

RECEIVE

MANUFACTURE

CHECK Processes &

Stds

DECIDE Schedule of Ops

TRANSPORT Products

STORE Products

COLLECT Fin'd Prods

RECEIVE Del'y Instrns

DISTRIBUTE

KNOW About Disposal

Facilities

RECEIVE Customer

Orders

MONITOR &

CONTROL All Other Activities

RECEIVE Info

ANALYSE Info

ASSEMBLE Info

INTERPRET Info

DISSEMINATE Info

KNOW

26

SOFT SYSTEMS METHOD

3. RELEVANT SYSTEMS AND ROOT DEFINITIONS

RS 1

RS 2

RS 3

RD 1

4. CONCEPTUAL MODEL

ABSTRACT

WORLD OF

SYSTEMS

THINKING

7. IMPLEMENT CHANGES

6. DEBATE ON FEASIBLE

AND DESIRABLE CHANGES

2. THE SITUATION ANALYSED

Rich Picture

Issue 1

Issue 2

Primary Task

REAL WORLD

1. THE PROBLEM

SITUATION UNSTRUCTURED

5. COMPARISON OF

4 WITH 2

27

SSM - STAGE 5 ‘Preparing An Agenda For Debate’

NOTES:

Some Activities may not feature on the Agenda for

Stage 6

Items 5 & 6 above may be completed as part of stage 6

Activity in CM

Exist Or Not?

Present Mechanism

Measure of Performance

Proposed Change

Comments

1 2 3 4 5 6

28

SSM - STAGE 6 ‘Debate’

WHO IS INVOLVED?

Client, Problem Owner(s), Problem Solver(s), Others

AIMS

To Agree Changes That Are:Systemically DesirableCulturally Feasible

WHAT IF CHANGES CANNOT BE AGREED?

This May Be A Wise Decision in Some Circumstances

Maybe Your Chosen Relevant System Is NOT Seen As

Relevant. If So, Repeat From Stage 2.

29

TYPES OF CHANGE THAT MIGHT COME ABOUT: Changes in Structure:

e.g. Organisational Groupings

Departments

Reporting Structures

Lines of Command

Lines of Functional Responsibility

Physical Layout Changes in Procedures

i.e. Different Ways of Doing Things Changes in Policy in the Goals & Strategies of the HAS

Being Investigated Changes in Attitude

SSM - STAGE 7 ‘Implementation’

30

Soft Systems MethodResume of Rules - Constitutive

Seven Stages, Many of Which Are

Iterative

Each Stage Has A Defined End-Product

CMs To Be Checked Against RD and

Formal Systems Model

CMs To Be Derived from RD Only. They

are NOT Descriptions of Systems to be

Engineered

Initial Exploration Should NOT be a

Search for Systems in the Problem

Situation