Changeability denotes the ability of a factory to adapt to new demands on one or more levels, depending on the impulse for change. In the Handbuch Fabrikplanung, Wiendahl, Reichardt and Nyhuis record that the term is to be demarcated from similar ones — changeover ability, flexibility, reconfigurability, transformability and agility — and they name the reason: to make it assessable.
That is where the practical core lies. Flexibility describes a pre-considered latitude within a given structure; changeability means the ability to alter the structure itself. Whoever equates the two is selling a machine with a broad part spectrum as a changeable factory.
Where the pressure comes from
The drivers of change are external and internal in nature. In essence they appear as volatility of demand and as a market-enforced variety of the range of services. A frequent driver besides these is a new corporate strategy, triggered by a change of owner or of management — an impulse that appears in no sales forecast and still overturns entire structures.
Change enablers — changeability can be built in
For a transformation to be possible at all, the systems must possess certain properties. The handbook calls them change enablers and defines them as an inherent property that can be activated within a given period and that brings about a desired change. They are derived from three system properties relevant to change:
The assignment is not a sorting exercise. Mobility together with expandability and reducibility belong to system dynamics and describe how far objects can be changed in location and area extent. Modularity together with functional and expansion neutrality hang on complexity and describe the ability to assume different system states. Networkability together with the ability to disintegrate and to integrate derive from interconnectedness.
For practical application, the authors note, these terms can be simplified further and reduced to five. What matters is the consequence: changeability is neither an attitude nor a promise but a set of properties that are built into buildings, equipment and organisation — or are not.
The problem changeability answers
Why the term is needed at all is stated precisely by Grundig in his Fabrikplanung. Planning and the later use of a factory are always to be understood as directly interdependent in their objectives and in the shaping of solutions — and in doing so it must be borne in mind that the two have an opposing character:
- The planning results have a (quasi-)static character. They can be altered afterwards only to a limited extent — or only at high financial cost.
- The use of the factory has a dynamic character. It is marked by the constant mutual adjustment of the factory and the production task.
That names the contradiction changeability resolves: a static result has to carry a dynamic operation. The change enablers are the attempt to build into the static result, from the outset, the mobility the operation will later need.
What this means for planning
Every change enabler costs something: mobility costs foundations and utility connections, modularity costs interfaces, expandability costs floor area that stands empty at first. What is planned is therefore not the maximally changeable factory but the one whose enablers match the drivers to be expected. Which drivers those are is clarified beforehand, for instance through scenario work.
The arrangement within the areas is described by layout planning. Why planning within an existing site is the normal case rather than the exception is treated under greenfield. How changeability is set against flexibility criterion by criterion is shown in flexibility or changeability.
Sources
Wiendahl, H.-P.; Reichardt, J.; Nyhuis, P. (2014): Handbuch Fabrikplanung — Konzept, Gestaltung und Umsetzung wandlungsfähiger Produktionsstätten. 2nd edition, Hanser; section 5. The systematics of change enablers goes back there to Hernández Morales, R. (2003): Systematik der Wandlungsfähigkeit in der Fabrikplanung and is reproduced here as a marked secondary citation. Grundig, C.-G. (2018): Fabrikplanung. 6th edition, Hanser, section 1.
Changeability in practice: Our services overview brings together the relevant planning and consulting approaches.