Before you even talk about what and how to implement the intent of a story, you can slice it in a way which will make it “smaller” in scope (and implementation time) by default.
You can do this by turning general terms in the story (aka the “seams”) into more specific examples for the:
Becoming more specific about the customer you are addressing with a story has the potential to narrow its scope. You can initially focus on a specific customer group which gives you a narrower focus for the capabilities you build first.
For example, in the superannuation domain, if you are looking to develop a suite of investment capabilities to help users of your superannuation product build their retirement wealth, you can first target older customers – who will likely be more interested in reducing risk and consolidating their existing funds – and defer any capabilities (or marketing) aimed at younger people who might want to increase risk to maximise returns:
As a personal superannuation customer aged over 55 and with a family I want to reduce the risk in my investment portfolio So that I can protect my retirement wealth
You can also use this technique to slice (be more specific about) user roles such as administrator (e.g. system administrator, project administrator, kanban board administrator). Again, this will allow you to focus on one type of administrator first, create working/shippable product and defer addressing the other types to a later date.
Consider a top level capability: “I want to do my banking online”. Try this – take the general term “do my banking”, and write down all the things you can think of which you do (or might want to) in the banking domain.
As with the customer, becoming more specific about the customer job gives you options to focus on first. In the banking domain, “I want to pay my bills online” is a slice (specific capability) underneath the story “I want to do my banking online”. So are “I want to transfer money online”, “I want to apply for loans online” and “I want to save money online”.
You can get even more specific (i.e. slice further) with each of these. “I want to pay my bills online with BPAY”, “I want to transfer money to my trading account online”, “I want to apply for a chattel mortgage online” or “I want to automatically top up my savings online”.
Regardless of how deep you slice, each of these are independently valuable capabilities which you can focus on first, and defer the rest. Each of them on their own would provide a working product which does something useful for a customer, should you release it to them. Even if you don’t think you want to release only one of these capabilities, developing one of them to a shippable state BEFORE moving onto another creates the possibility of releasing something earlier than if you batch up the capabilities, plus it shows demonstrable progress and enables feedback.