question: How does the LEGO company decide which pieces should they include duplicates of in a set?
comment: As a long time legoist, this seems to be almost exclusive to very small pieces and fairly random. I've never seen a set be short, but duplicate or triplicate of *some* small pieces is basically guaranteed. Other equally small pieces are not duplicated, which suggests this is a packing error they simply live with rather than a conscious decision. More generally in industry, part hoppers are allowed to exceed but never under-fill. Nobody's ever been sued for putting too many chips in the bag or including a few random extra washers.
passages: A challenge faced by the designers of these sets is that they are not able to work with the full palette of Lego bricks and colors ever produced when designing. Instead, they are limited to the bricks and colors currently in production by Lego at the time of the product design. As an example, for Café Corner, the designer wanted to include a bicycle piece in the set, but at the time, the machine that made bicycle pieces was broken. It had to be fixed in order for the designer to be able to include the piece in his design. With Market Street, the fan designer was limited to only the bricks and color combinations available as 'active components,' meaning bricks that were already in production. No new bricks could be introduced.
   Lego pieces of all varieties constitute a universal system. Despite variation in the design and the purposes of individual pieces over the years, each piece remains compatible in some way with existing pieces. Lego bricks from 1958 still interlock with those made in the current time, and Lego sets for young children are compatible with those made for teenagers. Six bricks of 2 × 4 studs can be combined in 915,103,765 ways.
   New building techniques introduced with this set include a systematic way of building numbers. On the front of the building the year 1932 appears, which is a reference to when LEGO was founded. The number 3 also appears on the pavement of the set representing that this is the 3rd set on the series from Lego set designer Jamie Berard (he had previously designed Café Corner and Green Grocer).
  
  Section::::Sets.:Grand Emporium.
   As part of the Design byME service, Lego has produced a computer program called Lego Digital Designer, which allows people to design a virtual Lego model using a selection of virtual Lego bricks. These models can be saved locally, as well as uploaded to the Lego website for sharing and ordering as a physical product.
  
  Section::::Discontinuation of service.
   Since the expiry of the last standing Lego patent in 1989, a number of companies have produced interlocking bricks that are similar to Lego bricks. The toy company Tyco Toys produced such bricks for a time; other competitors include Mega Bloks and Best-Lock. These competitor products are typically compatible with Lego bricks, and are often marketed at a lower cost than Lego sets.
   Lego Creator
  
  Lego Creator is a Lego theme. Creator sets have few specialized bricks, featuring generic themes such as buildings, dinosaurs, cars, robots, and wildlife. Since about 2006-2007, the sets have regularly featured instructions for three different possible builds from the bricks included.
  
  Section::::History.
  
  Formerly known as "Make and Create", Creator started with brick buckets and tubs, then switched jobs with Make and Create, the latter selling brick buckets and tubs, then renamed to "Bricks and More". An earlier theme X-Pods (now discontinued), had small builds included in small containers.
   Each Lego piece must be manufactured to an exacting degree of precision. When two pieces are engaged they must fit firmly, yet be easily disassembled. The machines that manufacture Lego bricks have tolerances as small as 10 micrometres.
   Lego have made Duplo sets licensed with Bob the Builder and Thomas & Friends characters. Those Duplo ranges have been discontinued, but Duplo sets now include farm, zoo, town, castle, and pirate lines. A doll house and princess castle are available as of 2008. Some Duplo sets have cars, trucks, and buildings which cannot be disassembled. Some DUPLO sets do not include building manuals.
  
  Section::::In other media.
   Lego clone
  
  A Lego clone is a line or brand of children's construction blocks which is mechanically compatible with Lego brand blocks, but is produced by another manufacturer. The blocks were originally patented by The Lego Group in 1961 as "toy building bricks", and the company has since remained dominant in this market. Some competitors have moved to take advantage of Lego brand recognition by advertising their own products as compatible with Lego, with statements such as "compatible with leading building bricks".
  
  The last underlying patents of the brick design expired in 1978, opening the field to rivals.
  
  Section::::Legal challenges.
   BULLET::::- Advantage Challenge: “Break and Make” - Teams were given four hours to take a lego parrot apart and build something new with all 1,600 pieces. The winner of the challenge received an advantage of an extra hour for the elimination challenge.
  
  BULLET::::- Elimination Challenge: “Apartment” - The Teams were given 11 hours to create an apartment complex with three flights of floors. The team with the weakest design were eliminated.
  
  Section::::Series Details.:Challenge 5.
  
  BULLET::::- Airdate - 6 May 2019
   There have been scheduling challenges faced in the design of the Modular Houses sets. For the Green Grocer set, the designer believed that the set could have benefited from another design iteration before release. The detailed nature of these sets requires a greater amount of design time than a normal Lego set. It is expected that future sets in the series will not suffer from such schedule pressures.
   The reason interiors were not included in the first two models in the series, Café Corner and Market Street, was because they could not be seen in the pictures included on the packaging. Once the success of Modular Buildings sets had been proven with these first two sets, for the third set, Green Grocer, the designer was allowed to include interior details in each of the floors. As a result, many of the interior details of later sets, such Green Grocer, are not visible on the box and are only discovered while building the set. However, the boxes of each set feature some of the interior details such as the escalators inside Grand Emporium and pool table inside Detective's Office.
   KiSS sets are allowed to acquire resources from other KiSS sets by a process called 'Expansion'. This allows new versions of a doll without incorporating the original cells into the new set, meaning that earlier versions did not have to be replaced, and different artists could add to the doll without confusion as to who the original artist was. This dates from some of the earliest viewers, but the details of loading an expansion set remain somewhat viewer dependent.
  
  Section::::Extensions.
   In October 2015, four new sets were released for Toys "R" Us Bricktober. They are 40141 - Bricktober Hotel (204 pcs), 40142 - Bricktober Train Station (180 pcs), 40143 -Bricktober Bakery (234 pcs), 40144 - Bricktober Toys "R" Us store (165 pcs). This time the base is 8x8 and 8x10 (and the boxes are thicker, but otherwise same size). As last time they each include two vehicles.
  
  Section::::Related sets.:Ninjago City.
   In 2011, Lego sued Guangdong Jumbo Grand Plastic Moulding Industrial over its compatible BanBao's copycat packaging. The two companies settled their case out of court with Guangdong agreeing to create unique packaging and a new figure, ToBees.
  
  In 2016, Lego announced that it would be taking legal action against the Chinese company Guangdong Loongon, which manufactures the brand Lepin, for selling exact replicas of existing Lego products (including box-art).
  
  Section::::Brands.
  
  †- blocks that Lego originally cloned
  
  BULLET::::- K'Nex sets have included compatible bricks since 2008.
  
  BULLET::::- Ramagon, by Discovery Toys, has some panels with compatible studs
  
  Section::::See also.
   Lego Designer Jamie Berard created many Modulars Buildings and decided to make a mini version of his set for fun. Five of these were then released as a single set 10230 containing 1356 pieces, each one on an 8x8 baseplate, making them quarter-scale with respect to the original buildings. Initially, this set was for Lego Group VIPs only, but it later became available for general sale.
   Most Playmobil sets require some assembly by the owner. Buildings especially come with detailed instructions for putting them together. Playmobil building parts were originally designed to fit together using a system of tabs and slots known as "Steck-System". In recent years a new construction system has been introduced that dispenses with the tabs and instead uses small connector pieces and a special tool. This is known as "System-X" and is now the standard Playmobil construction system, Steck-System having been retired except for special reissues.
   The Brick Bank also introduced some rare elements such as a metallized-paint gold ingot and coins (to be used with the coin-stacking machine play feature), and used the less-common colors of Sand Blue and Sand Green.
  
  Section::::Sets.:Assembly Square.
  
  Assembly Square (set number: 10255) is the twelfth set in the Modular Building line. It was released on 1 January 2017 at a MSRP of US$279/€239. This set contains the most pieces of any previous Modular set at 4002 pieces as well as the most minifigures: 9 (just barely by being the third LEGO set release to include an infant). 
   Section::::Design variations.
  
  While nearly all minifigure heads, torsos, arms, hands and legs are the same size and shape, some sets have included figures that deviate from the standard.
  
  One of the most extreme design variations was a minifigure produced in an edition of five of the Star Wars character C-3PO, cast in solid 14-karat gold.
  
  Section::::Design variations.:Torso.
   Lego Toy Story
  
  Lego "Toy Story" is a Lego theme based on the Disney·Pixar's "Toy Story" film franchise. The first four sets were released on December 30, 2009, with an additional two sets being released on January 4, 2010. In May, five Lego and four Duplo sets were released under the "Toy Story 3" sub-theme. For the release of "Toy Story 4" there was one duplo set based on the third film and 6 Lego sets based on the fourth film. These sets were released in March and in April of 2019 this time under the Juniors line.
  
  Section::::Sets.
  
  Section::::Sets.:Lego.
   This set marks the 10th Anniversary of the Modular building sets containing numerous "easter egg" references in use of brick elements, colors and architectural details to every Modular set released over the previous years.
  
  Section::::Sets.:Downtown Diner.
   In 2001, Lego re-released the well-known Guarded Inn, re-numbered (#10000) as a Lego Legend. The set consisted of two Lion Knights, a mounted Black Falcon Knight, and an inn keeper. This set was the only structure to include red Tudor walls. One change in the reissue was the horse saddle had two clips instead of one. Since 1984, Lego Castle had horse saddles with a single clip (except the horse barding saddles) at one side until 1992 when that was changed to two clips.
   For the first time since 2007's Market Street, the included 6 minifigures have individual, varied faces rather than the classic plain-smile-only faces used in Modular buildings over the past decade.
  
  Section::::Sets.:Corner Garage.
   Lego Design byME was created for people to build and experiment with virtual Lego bricks. This is done on a program called Lego Digital Designer. Models are uploaded to Design byME on the Lego website, and creations can either be shared with the world in the gallery or purchased as a custom Lego set.
  
  Section::::System.:Pricing.
  
  When purchasing models from Lego Design byME, the price was significantly high compared to store-bought Lego sets, leading consumers to believe that the prices were unreasonable. However, the price was divided into a few different parts. These are listed below:
   Sometimes in different sets, the Miners appear different from the way they usually look (e.g. hair, different facial expression, different hat) but most of the time they appear the same.
  
  Section::::Combo Models.
  
  Instructions for three combo models were provided by the official Lego website followed by 4 models made from pieces of specific set: (Information is Below)
  
  Stone Chopper + Mine Mech = Cave Cutter
  
  Granite Grinder + Thunder Driller = Aero Shredder
  
  Claw Digger + Crystal Sweeper = Crystal Crawler
  
  Pieces of the Underground Mining Station = Rubble Rescue Rover
  
  Pieces of the Titanium Command Rig = Rock Watchman
  
raw_presuppositions: The LEGO company makes a conscious and intentional decision about what duplicates to include in a set.
raw_corrections: The LEGO company includes duplicates as a packing error rather than a conscious decision.