5 Design Methodologies

A review of the existing design (and design management) process with its roots in analysis and reductionism, is followed by a revision involving interaction and purposive behavior.

General Solutions: Design in the Mass/Energy Domain

Demand-activated production is a radical shift from classical engineering design, which was the major paradigm for the first part of the 20th century.

Handling of Uncertainty: Respond to problem with
need to know - pre-analysis and reductionism

prediction - all cases handled in advance

control - rules for handling all cases

Intractable Complexity (story of trivial and non-trivial machines): it is impossible to handle all cases in advance

Worst Case Design: implementation will require maximum safety for worst case scenarios

Inefficiencies in implementation (and also in design): resources required for pre-construction analysis and construction expend large percentages of total effort for least-likely cases

Inflexibilities: final implementation cannot handle variation outside of design specification (shallowness); un-foreseen situations not handled well (brittleness)

Effect of Classical Design on Present-day Production

The primary uncertainty in the production chain (what will sell and when) is handled classically by maintaining inventory. This has a series of implications:
Large amounts of cash are tied up and non-liquid.

The investment that inventory represents is made before the moment of proximity, is inflexible, and adds considerable inertia to the system, which is therefore less able to respond to changes.

Because product is buffered at all points in the production chain, inefficiencies in production are simply concealed and hence cannot be identified and removed.

The efficiencies of classical "mass-production" are to be found in economies of scale and through-put; therefore the concern is for maintaining production schedules, and product quality becomes a concern when it is too late, i.e., after the production run has been made (at which point the inventory has been invested in useless results and the reasons for poor quality are probably lost).

Customer becomes too much a part of the QA process, which leads to customer dissatisfaction as well as added expense for the producer in repairing the problems.

Specific Solutions: Design in the Information Domain

Demand-activated production is based on the broader approach of cybernetic engineering design, which arose in the second half of the 20th Century.

For each point there are implications for new production methods (in contrast to classical design approach of General Solutions):

Handling of Uncertainty: emphasis on dynamic interaction using
error detection - variation from desired goal

error correction - active response to variation

regulation - monitoring for overall stability

Handling Complexity: responding dynamically with system's malleable structure
handling complexity with complexity

relinquishing need to understand non-trivial machines

eliminate hesitation in awaiting thorough understanding of citizen; instead, respond and interact

Design for coupling to environment: close connection to environment assures consistent data about current state for interpretation against goals

Concomitant efficiencies in design and implementation: effort expended on flexibility and dynamic response

Robustness and fault tolerance: system naturally more redundant, and is made to have a response to un-foreseen situations

The value-added is design. The implications for social productivity, GNP, and resources required to handle complexity are vast.