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Organizational approaches to requirements

Colin Potts

Georgia Tech

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The role of systems in organizations

An organization is the context for the system’s functions» Organization provides rationale for system

Some theoretical perspectives on organizations view them as systems» Sociotechnical systems theory» IS design is mixture of Human Activity System (HAS) redesign & technical design

HAS1 HAS2 IS

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Overview: SSM & BPR

Soft Systems Methodology (SSM)» A methodology for

understanding a HAS and stating recommendations for change

» Not specific to IS» Analysis of HAS

“pushes” change» Origins in STS action

research

Business Process Reengineering (BPR)» Philosophy of HAS

improvement; not a single methodology

» HAS is a collection of controllable processes

» Technology may “pull” HAS redesign

» Origins in Quality-Improvement movement practice

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Soft systems methodology

Collection (not rigid sequence) of interlinked analysis activities

Outward-directed(“real-world”) activities

Inward-directed(“systems”) activities

Problem situationunstructured

Problem situationexpressed

Rootdefinitions

Conceptualmodels

Real-world/systemcomparison

Feasible/desirablechanges

Implementation

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Rich pictures

A sketch illustrating the current situation

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CATWOE: stakeholder types

The HAS is described in terms of six key attributes:C = Client/customer (Who are beneficiaries of HAS?)

A = Actors (Who perform activities within the HAS?)

T = Transformation (What does the HAS do?)

W = Weltanschauung / worldview (What are the key assumptions behind the HAS?)

O = Owner (Who owns the HAS and can cause it to cease?)

E = Environment (What constraints exist on how the HAS works?)

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CATWOE Example:Meeting scheduling

C: Senior mgt. & office workers A: Office workers & admin. assts. T: Satisfy time utilization for

teamwork W: Busy people; coordination a pain O: Senior mgt. / IS dept. E: Calendar; corporate values

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Writing a root definition

Textual definition of HAS working in CATWOE attributes:A system, owned by senior management and

the IS department, operated by office workers and administrative assistants to utilize their time effectively for teamwork within the constraints of the calendar and corporate values.

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Conceptual modeling in SSM

Model what is “systemically desirable”» Informal flow diagram

callmtg

identifyprefs

monitor& control

timemake

resourcesavailable

negotiateschedule

needtomeet

indiv.workingprefs.

calendar

resourceconstraints

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Levels in SSM

Each subsystem of the conceptual model may be decomposed as a HAS

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Comparing the model with the world

Does the systemically desirable HAS correspond to the real-world HAS?» E.g. is conceptual model consistent with rich

picture?– obviously not a formal analysis process

» If not, where can improvements be made?– SSM does not have methods for reaching

consensus on change

» and what should an IS do to improve HAS?

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Team Exercise: “Quick-and-dirty” SSM

For the example system:» As a class:

(1) discuss the HAS context» In teams of 2-3:

(2) Draw a rich picture

(3) Discuss & write root definition for HAS

(4) Draw a conceptual model (top level)

(5) Identify v. high-level IS requirements» As a class:

(6) Discuss what you produce

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SSM: How to find out more

Several books.» Checkland & Scholes: Soft Systems

Methodology in Action– Classic, but not specific to IS

» Patching: Practical Soft Systems Analysis– More of an action guide

» Stowell & West: Client-Led Design– Specific to IS, but not strictly SSM

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Business process reengineering (BPR)

Basic thesis: an organization operates through a series of processes» Repeatable activities, roles, procedures & rules» Processes can be modeled, supported &

“enacted”

HAS is improved by redesigning processes

Scope of improvement

Local optimization

(e.g. TQM)

Radical redesign

(e.g. BPR)

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The role of IS in BPR

Needs “pull” vs. technology “push”Process

“What”

“How”

possible IS

identify howIS cansupportprocess

“How” potentialtechnology

“Where”

Candidateprocesses

select processesthat technology cansupport

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Organizational use cases

Use case = standard interaction between system and its environment» For an organizational use case, the system

is a HAS, envt. is the business envt. Dual models (same concepts used)

» “is”: how things are done» “ought”: envisioned improvement

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Example use cases for library

memberof public

librarian

publisher....

circulation

membership mgt.

stock mgt.

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Categories of business object

interface object performs tasks thatcommunicate withenvironment

e.g. customerservice assistant

control object coordinates part ofthe process

e.g. shelf stocker

entity object things handled inthe business

e.g. book

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Example object model

E.g. borrowing a book

memberof public

customer serviceassistant

borrowingpolicy

librarypatron

book

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Interaction diagramsCust. Svc.asst.

Borrowingpolicy

Patron Book

Member of public presents books

Customer service assistant checks membership card

Borrowing policy checks that member of public is library patron in good standing

Customer service assistant records books to be borrowed

Borrowing policy updates book record

Customer service assistant tells borrower due date

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Envisioning new processes

Consider possible use cases in an IS-supported HAS» Use analogies» Standard optimizations

For example» How is a library like a gas station?

– Borrowing stations like gas pumps?

» Remove assistant by having unattended check-out station

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Team exercise: BPR use cases

For the standard example:» as a class:

(1) Decide on a single business process

» in groups of 2-3:(2) Identify & categorize objects for process

(3) Draw an interaction diagram

(4) Envision new system & describe to class

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BPR: How to find out more

Several books» Hammer & Champy: Reengineering the

Corporation» Morris & Brandon: Reengineering your

Business» Johansson et al: Business Process

Reengineering» Jacobson et al: The Object Advantage

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Organizational methods: conclusion

Basic goal» Understand the context» Only then determine whether a system is

necessary, and if so where its boundary should be

Preconditions» Sense that something’s wrong or that an

opportunity beckons» No clear technical problem yet apparent