Stretch: how innovation continues once investment is made

Process industries are characterised by large fixed items of capital equipment. This paper asks how innovation takes place once these plants are built. Stretch is the mechanism by which established plants incorporate improvements in process and product technology, and make higher output and new products as a result. A taxonomy of ‘stretch’ is proposed looking at five interrelated features: improved intensity of hardware use through experience and better maintenance; system‐wide effects of improvements in feedstock and downstream processing; ‘bolt‐on goodies’ and physical reconstruction of existing plants; and quality enhancement and new products. Intensity of use encompasses familiar learning effects, but also enhanced maintenance. Evidence for stretch is given for wide strip mills built under Marshall Aid, but the concept has wider application across process industries, manufacturing, transport and services. From a theoretical point of view, stretch is the expression of evolutionary problem solving. The practical implication is that research and development management should encourage cross‐functional collaboration. Creative and unorthodox personnel need to work in routine areas such as maintenance. Results‐orientated production managers need to accept risky interventions in production schedules to allow continuing innovation.