Better Prioritization – Sequencing & Classes of Service Explained

 We don´t perform a specific activity to prioritize work for kanban systems. Instead we practice dynamic prioritization, selecting items of work on-the-spot, based on risk, or other desirable outcomes such as fairness, good customer service, or value. 

The term ¨prioritization¨ is proscribed in Kanbanland. Prioritization, re-prioritization, backlog gardening, are all busy work for someone, but they represent needless waste. Instead of the term, and the activity of, ¨prioritization¨, we prefer the explicit terms of selection, scheduling, sequencing, and class of service. 

• Selection – choosing one thing over other available options 
• Scheduling – determining when to start work on something (time sequencing) 

• Sequencing – ordering by preference, queuing 
• Classes of service – the policies, including the queuing discipline, usually determined by risk and/or value, that determine how something is treated once it has been accepted as work to be undertaken and delivered 

This article explains the power of sequencing and use of classes of service (in combination sometimes called ¨queuing discipline¨) and how these techniques are used in the real world to provide professional, high quality service. 

Background 

Since August I´ve been living in the Austrian Alps. Fiber to the premises (FTTP) means that Internet access is first class, and the high mountains seemed like the ideal place to spend time during a pandemic. Plenty of fresh air and hiking have fueled my brain with oxygen and I´ve been highly productive creating new materials and ideas.  

I spend my days in a combination of walking or biking in the mountains, sitting taking hot chocolate and homemade cakes in Alpine huts, and working online from my apartment. Austria is famous for its hospitality and the level of service in its tourism industry. I´ve been studying how, often a single waitress, keeps a fully occupied garden with 15-20 tables of guests, satisfied and well-served. The waitress employs 4 basic classes of service and queuing discipline, with an option on a fifth. To fully understand this you have to know how to translate what the waitress means, and not just what she says (see table). 

Classes of Service in the Alps 

These are the four basic classes of service of an Alpine hut, and from them you can see the queuing discipline is typically FIFO (first in, first out), unless someone has a reason to jump the queue.  

¨Entschuldigen Sie bitte. Wir fahren um halb drei Uhr mit der Seilbahn . Wenn moeglich, kannst Du uns schnell zwei Kaffee bringen?¨ Two of my English friends, who´ve lived here for over 20 years, ask the waitress for the Fixed Delivery Date class of service. ¨Excuse me please, we are taking the 2.30pm cable car. If possible, can you bring us two coffees quickly?¨ 

She likes them, and answers. ¨Passt! Kommt sofort.¨ Their request to jump the queue has been approved. 

And hence, we have the fifth class of service, fixed date, based on urgency, familiarity, and frequency of repeat business – regular customers who normally wait in line like everyone else, can get privileges from time-to-time. 

Dynamic Queue Management 

The waitress doesn´t prioritize her backlog and reprioritize it. Instead she dynamically manages the queue based on unwritten policies of fairness, customer service, and value to the business. This comes naturally to her. Any other way would be unimaginable.  

Work Item Types 

There are two basic types of request: requests for service – food and drinks; requests to pay the bill. For the most part both types are treated with the same policies – ordering doesn´t take precedence over settling up, nor the reverse. If circumstances changed and a queue formed waiting for a table, then perhaps settling up, clearing and cleaning tables would get some slight preference, but under normal demand loads this is not the case. And now we see again the possibility for a dynamic and subtle shift in policy, when demand is unusually high, requests to pay take priority over requests for ¨Noch eine cappuccino¨ (another cappuccino please). 

Conclusion: Selection and sequencing, not prioritization 

The waitress selects the service requests, sequences the customers, and adjusts the queue of waiting customers dynamically. While customers may be given priority, like my English friends rushing for the cable car, the backlog is never prioritized, or reprioritized. Just 5 classes of service are sufficient to provide a sustainable level of acceptable customer service. 

To learn more about classes of service check the Triage chapters in «Kanban Maturity Model», 2nd edition or via kmm.plus. Visit djaa.com to take part in the next KMM class with David J. Anderson.