Here we are going to take a look at the types of shift pattern.  Like most things in life people have different descriptions about how they see things and this is ours.

A shift pattern is a sequences of shifts in the context of each other and in the context of days-off. At a more primitive level it can be described as a day-on day-off pattern. All shift patterns have a sequence, but not all sequences are based on the same factors. Some are based on days of the week (easy), others are based on days-on days-off independent of days of the week (harder), and others are based on a group of factors which must always succeed to generate a pattern (very hard).

Arguably you can have a shift pattern that is totally random but that is hard in practice. It will not be the first time I have been told “…they work whatever they want when they want…and there is no pattern”. You usually can identify a pattern in around three to four weeks which proves remarkably robust for the remainder of the year – it’s just they can’t see it. And before you blog me with examples of random shift patterns generated by a computer, the key words I use are hard in practice. The reason is because we all virtually live our lives in patterns of time. It’s just a simple question whose pattern (or schedule if you like) wins – usually the one that can’t see the pattern loses.

I was chatting to a cable guy who was fixing my TV about his new shift patterns being worked out ( a coincidence although I do bore for England on this subject). I uttered some words of sympathy about the 24/7 community and globalization affects us all. Not a bit of it. “They are still working it out he retorted …and as I already have mine they took one look and said that looks good, now everybody has to work it.” I was impressed and asked him how he went about it.  “Easy, I know the away matches for Arsenal and I can still fit their home matches in so the wife can still do her part-time job”. 

So a whole workforce deployment strategy is being being driven by the FA Premiership fixtures and Arsenal football club away matches with a little help from the wife’s part-time job – but only he could see the pattern. So take the time to understand shift patterns and you will elevate yourself above mere mortals to a higher plane. On the other hand if you feel it’s not that important – good luck!

Back to the shift pattern types. There are three:

1. Weekday Generated Sequences (WGS) is a shift pattern that references the days of the week for its structure and design e.g. repeating days-off always occur on the same days of the week in rotation, or the Wednesday and Thursday of the third week is the afternoon shift etc. The most obvious is always having the days-off at the weekend. These patterns are always structured in multiples of seven e.g. 7, 14, 21 because that is a week.
2. Pattern Generated Sequence (PGS) is a shift pattern that uses a sequence of day-on day-off which is independent of the days of the week. For example 4 days working followed by 5 days not working. These patterns rarely fit into multiples of seven. They also give rise to the notion of the “eight day week” when the sequence is eight days long. It doesn’t help because a week is seven days not eight days.
3. IA Generated Sequence (IAGS) No not AI for artificial intelligence, but IA for intelligent agents. We use intelligent agents to automatically generate shift patterns when one or more factors are well-defined. Thay are very good at knowing when a goal is reached and when a solution fails it remembers where it is and doesn’t start from the beginning again  which is a big time saver. You can find all the shift patterns that succeed and chose the one you want,  if there is more than one ( or modify it manually if you want to ruin it). The advantage – apart from being fast – is the knowledge you have all the possible shift pattern solutions. If seven shift patterns suceed there will not be an eighth lurking around. The search space invariably involve very large numbers of shift patterns.

As a general rule the best approach is not to try and use one shift pattern to manage complex working arrangements. It is better to design simple shift patterns that each achieve a goal, and then combine them together in one schedule. You can even combine the different types of shift pattern above in the same schedule.

 The schedule being greater than the sum of its shift patterns  ;-)

See: Shift Pattern Glossary