of life and death in organisms, cities and companies. Weidenfeld & Nicolson. How much food do we need to stay alive? How creative are we? How profitable are our companies?
of life and death in organisms, cities and companies. Weidenfeld & Nicolson. How much food do we need to stay alive? How creative are we? How profitable are our companies?
of life and death in organisms, cities and companies. Weidenfeld & Nicolson. How much food do we need to stay alive? How creative are we? How profitable are our companies?
of life and death in organisms, cities and companies. Weidenfeld & Nicolson. How much food do we need to stay alive? How creative are we? How profitable are our companies?
Coupling Functional Coupling Model Coupling Contract Coupling • How the parts of the system are implemented • Private interfaces • Not intended for inter-component integration
Coupling Functional Coupling Model Coupling Contract Coupling • Knowledge of what the system has to do • Business logic • Use cases • Rules, invariants, constraints
Coupling Functional Coupling Model Coupling Contract Coupling • Models of the business domain • Data structures • Software system-related aspects of the business domain • Understanding of the functional requirements
Coupling Functional Coupling Model Coupling Contract Coupling • Components’ integration contracts • Integration-specific models, APIs • The minimal data needed for components to work together
in, what’s out, what spans, what moves between), and about tradeo ff s. It reshapes what is outside, just as it shapes what is inside.” - Ruth Malan (@ruthmalan)
1.8kg 3.5kg 7kg 14.5kg 29kg 58kg BASAL METABOLIC RATE The minimum number of calories a day needed to stay alive without performing any activities. https://www.sciencedirect.com/topics/engineering/basal-metabolic-rate
increasing the size of structures to vast dimensions either in art or in nature; … also it would be impossible to build up the bony structures of men, horses, or other animals so as to hold together and perform their normal functions . . . for if his height be increased inordinately he will fall and be crushed under his own weight.” - Galileo Galilei
the overall weight • The amount of cells surpasses capillaries’ ability to supply energy • All available energy used for repairing consequences of entropy CITIES • Overcrowding • Crime rates • Pollution • Spread of diseases COMPANIES • Sublinear scaling of sales, incomes, and profits • Bureaucracy • Administration and management complexity SOFTWARE SYSTEMS ?
number seven, plus or minus two: Some limits on our capacity for processing information. Psychological Review, 101(2), 343–352 ESTIMATED CAPACITY FOR PROCESSING INFORMATION 2000s: 4 +/- 1 Cowan, Nelson. "The magical number 4 in short-term memory: A reconsideration of mental storage capacity." Behavioral and brain sciences 24.1 (2001): 87-114.
length has been increased three times and whose thickness has been multiplied until, for a correspondingly large animal, it would perform the same function which the small bone performs for its small animal” - Galileo Galilei
great giant the same proportion of limb as that found in an ordinary man he must find a harder and stronger material for making the bones” - Galileo Galilei
Water Mill Gunpowder Printing Press Optical Lens Steam Engine Telegraph Plastics Airplane Transistor Nuclear Power Space Flight Internet Mobile Technology
great giant the same proportion of limb as that found in an ordinary man he must find a harder and stronger material for making the bones” - Galileo Galilei
length has been increased three times and whose thickness has been multiplied until, for a correspondingly large animal, it would perform the same function which the small bone performs for its small animal” - Galileo Galilei
ecosystems, cities, or corporations, require the close integration of enormous numbers of their constituent units that need e ff icient servicing at all scales. This has been accomplished in living systems by evolving fractal-like, hierarchical branching network systems.” - Geo ff rey West
pressure drop in fractal tree-like microchannel nets Lorthois, Sylvie, and Francis Cassot. "Fractal analysis of vascular networks: insights from morphogenesis." Journal of theoretical biology 262.4 (2010): 614-633.
Local Complexity Loose Coupling Global Complexity LOW DISTANCE HIGH DISTANCE • High cost of cascading changes • High shared knowledge • Frequent cascading changes
possible 2. Balance integration strength and distance • Both are high? — Reduce distance • Both are low? — Increase distance 3. Repeat at all levels of abstraction APPLYING M=S^D
for dealing with complexity is abstraction. Many types of abstraction can be used, but encapsulation is the main form of abstraction by which complexity is managed in object-oriented programming.” - Rebecca Wirfs-Brock