Control Advent Calendar

Christmas is coming soon, which puts everyone into high gear. Santa and his elves are preparing everything for their big gift-giving night. They tinker, refine and plan so that everything can run smoothly. They remember last year and how chaotic … Continue reading19 – Which strategy should Santa choose?

This year, Santa’s castle is abuzz with excitement as the elves enthusiastically participate in the inaugural Christmas Contest for Gingerbread House Baking. Each elf is putting forth their unique recipe for crafting this beloved sweet decoration. These recipes include specific … Continue reading18 – How stable is Mary Christmas’s gingerbread house recipe?

Remember the network at Candy-Workshop 3 of who follows whom: Keep in mind that if one elf follows another, the reverse does not necessarily apply. Also, if an elf follows another elf, it means that they take over the opinion … Continue reading17 – Who Knows What Happened Last Night in Candy-Workshop 3?

In the gift factory of the North Pole, many processes use vapor pressure to work.The vapor pressure is controlled by opening and closing a valve. In the past, this valve was controlled using a simple analog on/off controller. Unfortunately, this … Continue reading16 – How to fix the magical solution?

In Santa’s workshop, preparations are in full swing: gifts from all the different workshops arrive on a conveyor belt at the gift wrapping station, where the elves wrap them up. But there is a problem. When large, heavy gifts coe … Continue reading15 – Mission: Avoid gift congestion

Santa is known for many traits such as his love of red clothing and his long white beard. A well-kept secret is that Santa’s beard grows exactly 1 cm per week. What is charming for some, however, causes extra work for … Continue reading14 – Which beard-trimming proposal should Santa choose?

The elves play different games during the weekends. The main aspect for them is that every rule is followed, the games are fair and everybody is having fun. Today, they agreed to play a round of “elf chess” where one … Continue reading13 – Fancy a round of elf chess?

Santa’s sleigh must be taken to one of four special sleigh workshops for inspections.One of these workshops is specially designed to keep the sleigh stable – but Santa has a small problem: he has completely forgotten which one is the … Continue reading12 – Which Workshop should the sleigh be taken to?

Santa continues refining the temperature-control system of his Christmas Hot Cocoa Machine. To train the elves, he asks them to explain what feedback really means. Five enthusiastic elves step forward… with five very different answers. Which elf is actually describing … Continue reading11 – What does feedback really mean?

Influencer is a new and trendy profession and for sure even elves are on social media and spread the news among themselves. At Candy-Workshop 3 there is an interesting network of who follows whom: Keep in mind that if one … Continue reading10 – Who to target as an elf-influencer?

For the annual Grand Elf Light Show, five elves are tasked with walking around the courtyard (see the map) while each holding the end of a light chain, with which they dramatically wave around in time to the music. The … Continue reading09 – Will the Grand Elf Light Show go smoothly—or end in a…

Santa wants to upgrade his legendary Christmas Hot Cocoa Boiler so it can keep up when he changes his mind — which he often does — about how sweet the cocoa should be. To help him, the elves designed a … Continue reading08 – Will the Elf-by-Elf sweetness regulation work as planned?

Elf Elfis is in charge of keeping a pot of warm punch cozy for the elves’ winter party. The punch is heated by placing candles under the pot. He knows that when the room temperature is 22 °C and he places … Continue reading07 – Two candles for the perfect cup of punch?

Santa is determined to keep the temperature inside his Christmas Workshop perfectly stable. But every now and then, when someone opens the giant wooden workshop door, a cold North-Pole draft blows in and chills the room. From previous experiments, the … Continue reading06 – Who controls the workshop temperature best?

The elves are out for a fun skating adventure! The ice rink is partly a frozen lake on the right side and partly an over-frozen meadow on the left side of the plot. (The border between the two areas is … Continue reading05 – How many cookies should the elves eat to stay safe on…

Santa is building a huge gingerbread house at the North Pole, but he’s worried it might not stay standing once it’s covered in holiday decorations and delightful treats. The stability of this sweet creation depends on how many candy canes … Continue reading04 – Will the gingerbread house be stable?

It is a frosty Christmas Eve, and Santa is getting ready for his big night of delivering gifts. The sleigh is loaded, the stars are twinkling, but there is one problem – his reindeer have picked up a strange habit. … Continue reading03 – Will Santa’s reindeer reach the magic 88 mph on Christmas Eve?

Santa has parked his red sleigh – due to lack of time in forward direction – in a parking lot perpendicular to the road and left from the yellow Ferrari of the Easter rabbit. (It will be a mess getting … Continue reading02 – How was Easter Bunny’s Ferrari parked when it hit Santa’s sleigh?

This year, the North Pole has been buried under record-breaking snowfall — so much, in fact, that entire workshops briefly vanished under snowdrifts taller than Santa’s sleigh. The elves are exhausted from nonstop shovelling, the reindeer keep losing track of … Continue reading01 – How should Santa deal with the north pole snow chaos?

The holidays are upon us, and it’s time to embrace the magic of the season! From baking warm gingerbread cookies to spreading kindness through good deeds, fetching logs for the fire, and choosing just the right holiday cards – Christmas … Continue reading🎄 Welcome to the 2025 Control Advent Calendar! 🎄