Hard Systems Model of Change (HSMC) – based on methods from systems engineering (SE), operational research (OR) and project management (PM). With HSMC, easier to determine objectives, find options for action and test them against criteria. HSMC has three phases: 1) Description Description of current system. Explain why change is Continue Reading
02 – Understanding Systems
Module
Role of Hard Systems
Hard Systems prevalent way of viewing world. Operational Research (OR) developed in 1940s, during World War 2 by Allied forces. Quantitative techniques and incorporation of logistics. Used to plan and deploy resources in Normandy beach landing. Also used in Enigma project – German submarine code cracking. Hard systems approach systematically Continue Reading
Introduction
Looking at two case studies focussing on agricultural industries and world of information systems. Illustrating complexity of modern world and interdependence of disparate players. Environment consists of many complex systems – biological systems to ecosystems to economic systems. Complex systems have many common structural and functional features – can be Continue Reading
Classification of Hard and Soft Systems
Problem situations classified along two dimensions, according to Jackson and Keys (1984): complexity – number of of elements and their interactions divergence of values and interests Low complexity – few elements and well-defined, linear, stationary interactions. High complexity – many elements, many interrelationships, dynamic and not well-understood relationships in turbulent Continue Reading
Hard Systems – introduction
Systems Thinking has concept of Hard and Soft Systems as previously covered. Hard Systems traditional approach from 1930s. Soft Systems formalised by Peter Checkland in 1970s. Examples of Hard Systems approaches: traditional MS/OR RAND (developed around 1955) systems engineering system dynamics (developed 1956) Approaches based on following assumptions: Clearly defined Continue Reading
Standard Development Lifecycle
1960s – first significant model developed – Standard Development Life Cycle (SDLC), also known as waterfall method. Splits software development process into stages: Requirements Analysis Design Build Test Implementation Maintenance Model has high level of abstraction – seven stages. No models have lower abstraction guiding development process. Has Systems Thinking Continue Reading
Development Models Introduction
Will be discussing models used in Systems Engineering field with emphasis on software development process and role of models in Information Systems design. Specifically look at role models play in development of software-based systems. These models used across other engineering disciplines, original mnemonic SDLC stood for Standard Development Life Cycle. Continue Reading
Iteration
Important concept and practise. Repeat analysis process several times to identify/enhance facts, data and understanding. Iteration, along with different views, helps produce robust analysis.
Activity Sequence Diagram
Also known as network diagram or critical path diagram. Show sequence of activities with linkages and dependencies. If critical path then timescales are involved.
Flow Block Diagrams
Maps flow of processes. Focuses on elements/components involved in flow of materials or instructions.