Action Centered Design

By

Peter Denning & Pamela Dargan

Peter Denning- Several prominent teaching and research posts.- President of the ACM- Spearheaded National Computing Curriculum Taskforce (1989)

– Denning Report- Presently, Chairman of the Computer Science Department at the Naval Postgraduate School in Monterey, California

PublicationsWorking Sets and Virtual Memory Great Principles of Computing Professions and Futures Software Engineering, Architecture, and Quality Workflow and Commerce

Pamela Dargan

- MITRE Corporation,- Experienced Software designer belonging to MITRE

Problem Statement

How successful software designers had managed to create software that users found usable and well suited to their needs

Interesting Statistics

In Use Never delivered Delivered but not used

50%

25%

2%

Fund Allocation

Software

US Govt. Accounting Office Review : Dept of Defense

Action – Centered Design

A broader interpretation of design that is based on observing the repetitive actions of people in a domain and connecting those action-processes to supportive software technologies

Approaches to Software Design

Primary Meaning of Design : “ To make or conceive a plan”

There are two principal approaches to it :

Product Centered Design (Software Engineering) : Dated to 1960 “Based on the traditions of engineering, where design is seen as a formal process of defining specifications and deriving a system from them”.

Human Centered Design Dated to 1980 “Designers immerse themselves in the everyday routines and concerns of the customers”

Product Centered Design (Software Engineering) :

The engineering design process operates on 3 assumptions:

1. The result of the design is a product (artifact, machine, or system).2. The product is derived from specifications given by the customer; in principle, with enough knowledge and computing power, this derivation could be mechanized.3. Once the customer and designer have agreed on the specifications, there is little

need for contact between them until delivery.

Human Centered Design

Based on understanding the domain of work in which the people are engaged, how they interact Computers, and programming computers to do exactly the same.

The engineering design process operates on 3 assumptions:

1. The result of the design is a satisfied customer.

2. The process of design is a collaboration between designers and customers; it evolves and adapts to their changing concerns, and it produces a specification as an important byproduct.

3. The customer and designer are in constant communication during the entire process.

Donald Norman :

Product-Centered design : Focus on the machine and its efficiency, expecting humans to adapt.

Human centered design : Leaves to humans the actions that humans do well such as understanding, empathizing, perceiving etc. and leaves to

machines what humans do not do well, such as performing repetitive actions without error, searching large data sets, accurate calculations.

Action-Centered Design

“ Software designers must be trained to be skilled observers of the domain of action in which a particular community of people engage, so that the designers can produce software that the designers can produce software that assists people in performing those actions more effectively”

Pattern Mapping as a basis for a Discipline of Design

The maps would provide ways

1. To convey the patterns of action of the domain in which the software will be used, in terms of its basic distinctions, repetitive processes, standards of assessment, strategies, tools, breakdowns, and driving concerns

2. To connect the linguistic structure of the domain to the software structures that will support the patterns, and to guide software engineers in implementing those structures

3. To provide a basis for measuring the effectiveness of the implemented system in practice

The basic patterns that these maps should cover are

• A set of linguistic distinctions (verbs, nouns, jargon, etc) • A set of speech acts by which domain participants declare and report states of affairs.• A set of standard practices (recurrent actions, organizational processes, roles, standards of assessment) in which members of the domain engage.• A set of ready-to-hand tools and equipment that people use to perform Actions . • A set of breakdowns, which are interruptions of standard practices and progress caused by tools breaking, people failing to complete agreements, external circumstances, etc. • A set of ongoing concerns of the people in the domain -- common missions, interests, and fears.

Summary

Building this framework in which software will be used, Representing it as a pattern language in a standard notation & Coordinating the work of builders is the central activity of a software architect.

Practice of these skills is Action-Centered Design

Quick Look

Action-centered design: Consists of

-- Observing a domain, -- Constructing a workflow map, -- Constructing a process/task-network map, and the connections between them. -- Review with the client and discuss as to how the system will satisfy each concern, -- Coordinate the implementation of the system with the software engineers.

Profile

Business process domain: The designers of the business process domain

-- Identify the structures of workflow.

-- Organize the information systems around these structures.

Work & Levels of Work Process:

Work : Is a network of commitments and actions, supported by

information devices.

Levels :

Material Processes

Information Processes

Business Processes

Material Processes :

The material process level deals with description of the physical activity involved.

For example: In a factory automation setup; this level would involve transformation and assembly of product units.

Information Processes :

While the material process fails to capture what is important about everyday activity, the information processes helps in understanding the same.

For examples: Technologies such as dataflow analysis, database storage and retrieval, transaction processing and network communication have provided a structure for effective information processing.

Business Processes:

The information from the information process would only be useful when someone can do something with it.

The significance of this activity lies in the request for the performer (service provider) to perform particular actions, in return for which the customer is committed to perform other actions.

Goal: Identify and design the basic structure of work in the business-process dimension: workflows, roles, acts and incompletions.

Workflow Structure:

This involves person-person transaction(Action Workflow), in which one person fulfills a request to the satisfaction of the other.

It is depicted as a sequence of four stages: Request, Negotiation, Performance, Completion.

The workflow could be represented on the maps as loops

Movement from one state to another stage occurs when one of the participants produces a speech act. The person who would be making the request would be the customer and the one serving the request is the performer. The performer in turn, might turn to other people for help and hence initiate a secondary action workflow and the main loop performer is now the customer.

The designer now

Analyzes the workflow structure and find possibilities for improvement and new functionalities. Uses the computer-based mapping tools that would enable the creation of work flow diagrams With this the designer would be able to answer the questions such as :

Who the customers and performers are. Conditions of satisfaction. The four stages carried out. The relationship between the loops.

New opportunities to improve come from the ability to identify, observe and anticipate potential breakdowns.