I have already completed three blogs on the topic of design principles – design principles – how to get good ones, more on design principles and understanding design principles  .   But I was recently approached by my son, who is working for Accenture and wanted some guidance on design principles.  So let me try to summarize here most of what I know about design principles.

First, design principles are the first level of design work.   Whether you are designing an operating model, an organisation model or a new product, you need to start by defining what you are trying to do: what good will look like.   For example “the operating model must enable us to deliver to customers within 24 hours of receiving an order”.   Inevitably, there can be a confusion here between objectives/goals and design principles.  But the confusion is healthy.  The process of defining design principles is often also a process of clarifying the goals.

Second, there are multiple levels of design principles, as there are multiple levels of design work – rough sketch, blueprint, detailed specifications, etc.  It is important to know what level you are working at.  It is also important to understand the hierarchy of thought and priority that is provided by the levels.  So you need design principles at an appropriate level for each bit of design work you are doing.

Third at each level, developing design principles is a creative/design act rather than a linear progression.  Design principles cannot be created with a “paint by numbers” tool.  While there is a cascade of thought from high level design principles to lower level principles there is no one-to-one link between higher and lower levels: a principle at a lower level may be informed by multiple principles at a higher level.   For example,  “warehouses should be located so that all major towns can be reached within 4 hours” could be informed by needing to deliver within 24 hours, needing to keep costs down and needing to ensure drivers do no more than an 8 hour shift.

Fourth,  there is a difference between design principles and “requirements” or “customer needs”.   Design principles define which “requirements” or “needs” will be given priority and what implications this has for the design.   So design principles are “strategic”, meaning that they help you decide between alternative priorities and they are the first creative act because they start constraining the design choices.

Fifth, design principles can come from a variety of sources:

+ strategic objectives/goals (or higher level design principles),

+ constraints,

+ stakeholder requirements,

+ knowledge about the strengths and weaknesses of the “as is” situation …. if there is one, and

+ knowledge about which capabilities will be critical to success in the future .

I personally like to check my design principles against stakeholder requirements to make sure that I have not overlooked the needs of a stakeholder.  But, it is helpful to define a “mission” stakeholder for the design work: the primary beneficiary.  This stops the needs of less important stakeholders unbalancing the design.

Sixth, there is an art in writing design principles which starts with challenging any statement with three challenges

• is there a choice being made between realistic alternatives? (Try the negative or lay out a scale and define where on the scale the principle is positioned.  Or try the Executive Attention test: will this design principle spark debate among those executives concerned about this bit of design? )
• does the principle narrow the solution space? (What options is the principle excluding or steering you away from or towards?)
• is it clear why this principle exists and is important? (How does it link to strategic objectives, constraints or stakeholder needs?  Ask the five whys.)

Time spent redrafting design principles or debating the meaning of design principles is rarely wasted.

Seventh, there is value in keeping the number of design principles at each level below ten.   The human mind can only juggle five or six or seven things at the same time, so a set of principles twice this number is less useful.  It is hard for a long list to influence the creative/intuitive act in a balanced way.   Limiting the number also helps force thinking about the “hierarchy of thought”.  As a colleague of mine likes to call it …. the Spice girls question ….”tell me what you want, what you really really want”.  So two or three design principles can be more useful than seven.