This article originally appeared on Forbes.com.

Banks have a stiff challenge with meeting consumer expectations for digital tools, as people grow accustomed to simple, convenient digital channels in other parts of their lives. Consumers young and old prefer using websites and mobile applications for their routine banking transactions, Bain & Company found in our recent survey of 133,171 banking customers in 22 countries. In the U.K., for example, consumers give an average Net Promoter Score (a key metric of loyalty) of 35 to their routine transactions done digitally, higher than the 20 points for transactions done through employees at the branch or call center.

Moreover, banks have barely touched some technologies that have reached a tipping point in consumer markets. In Australia, the UK and the US, 5% to 6% of consumers already use voice assistants for banking; between one-fifth and one-quarter are open to trying the technology for their banking in future.

Beyond the loyalty benefits, there are compelling cost reasons to accelerate development of digital channels that can handle routine transactions and move them out of expensive branches and call centers. Each mobile interaction incurs a variable cost that's a tiny fraction of the cost for a teller or call-agent interaction. As interactions migrate to mobile, a bank needs fewer tellers and call-center agents.

Cost implications also show up in nonroutine events like disputing fees. In the US, there's a significant gap between the leading and the lagging banks in the incidence of these dispute events. Laggards not only suffer from having more detractors among customers as a result, they also bear roughly twice the cost of resolving the dispute as the leaders do. In some cases, this can exceed any differences in the revenues collected from the fees themselves. It's better to eliminate such events in the first place.

Organizing around customer episodes, not products

We have seen some banks handle these challenges by organizing in a new way, around how customers experience the business. That's a marked departure from the standard, internally oriented approach to organizing around products and functions, such as the checking account or the risk-management function. As part of shifting to the customer experience, a few pioneering banks have adopted as a key unit of management the "episode"—activities that customers perform when they have a task to complete or a need to fulfill. Typical episodes include "I want to pay a bill online," or "I want to buy a home," or "I want to dispute a fee."

Design and management of each episode occur through small, cross-functional teams that are responsible for owning and improving an individual episode. Teams typically use Agile methods to quickly arrive at a minimum viable product, gathering and baking feedback from customers into successive versions of the episode before rolling it out broadly. One bank has managed to take Agile episode management to scale, with more than 250 active teams. The bank is realizing substantial gains as a result. For instance, one team generated an auto-finance mobile prototype in one week, a project that previously would have taken at least six months.

Different episodes require a different blend of digital and human processes, tuned to the unique considerations of each episode. High-stakes, emotional moments of truth, such as handling a complaint, demand outstanding customer service, as our survey respondents strongly prefer working with employees to dispute a fee or resolve a problem. Low-stakes, but frequent, episodes such as reviewing one's account activity should be as fast and convenient as possible through digital channels.

If banks don't reorient their approach and radically accelerate their rate of progress in digital, loyalty will suffer, and they will watch large technology firms such as Amazon and Alibaba poach more business. Meanwhile, their economics will erode as too many routine transactions continue to flow through expensive branch and call-center networks.

Bank employees, used judiciously, will also figure in this competitive battle, as long as they are deployed to resolve complicated problems or serve high-value customers that merit personalized attention. Banks that go a step further to mobilize small teams around individual customer episodes stand to steadily earn greater advocacy and loyalty, the best defense against incursions by technology firms.

Gerard du Toit and Maureen Burns are partners with Bain & Company's Financial Services practice.