Good Design

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Good Design

• Still an art practiced by craftsmen, not an
  engineering discipline

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Some Designs are Classics
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Question

• How do you recognize a great design?

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Answer

• All your competitors file for bankruptcy because
  you took away all of their customers.

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So what?

• How do you design great software? Very few
  software designers even think about driving
  competitors out of business when they design
  software.

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A really stupid idea

• When I first studied systems analysis about 1980,
  many authorities recommended that you begin by
  modeling the existing system.
• That is almost the worst possible way to design a
  system, especially in those days when computers
  were essentially automating existing manual
  systems.

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Why is that stupid?

• Modeling the existing system almost guarantees
  that you will reproduce the existing system with
  some automation.
• For example, you will probably keep some
  activities that are unnecessary in an automated
  system just because they were necessary in a
  manual system. Your system will be inefficient
  and overstaffed.
• You will tend to keep all the problems of the old
  system and introduce new problems as well!

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Example of saving the old
The mechanism that opens a car window was
designed to be operated by a hand crank at a
comfortable position for a person seated in the
car. It is unnecessarily complex due to its off
center location and the need to obtain leverage.
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Power windows

• Most car manufacturers just put a motor where the
  crank was. But that required extra power, extra
  weight, and a stronger lever that was prone to
  failure.

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A Better Design?

• With a straight toothed lever, you could use a
  smaller motor, save weight, save money, use less
  leverage, and have more reliability and better
  gas mileage. By saving 10 pounds per car, you
  could save the equivalent of one car for every
  350 cars made.

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Actual Power Window Types
Scissors type
Cable type
Bowden type
Examples from Italian Manufacturer ElectricLife
Windows
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Optimization

• In a competitive economy, over time inefficient
  practices tend to be eliminated as business finds
  better (more profitable) ways to do the same
  things. Businesses that use the older ways tend
  to go broke.
• But all systems can only be optimized around
  present resources. A good new resource, such as
  a computer, always changes the optimal strategy.

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Disintermediation

• Most of the productivity gains from computers
  have come from disintermediation. That is a
  fancy term that basically means cutting out the
  middleman.
• A computer is primarily a communications tool.
  Efficient communication allows us to avoid
  unnecessary tasks and costs.

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Example

• Most large companies have flattened their
  hierarchies since automation, getting rid of
  middle managers.
• The two primary tasks of middle management were
  to gather information from subordinates to pass
  on to upper management and to communicate the
  policies of upper management to the workers. If
  communication is automated, fewer people need to
  do it.
• That is disintermediation.

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Another example

• Small merchants are not as efficient as (good)
  large merchants. They can not get big discounts
  by ordering in truckload quantities. They
  survive on convenience and lack of price
  competition.
• Around 1970, large malls started to be built all
  around the United States. Whenever a new mall
  was built, many small merchants were driven out
  of business.
• In smaller towns, Wal-Mart had the same effect.

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Knowledge is power

• Merchants survive by charging more for goods than
  they pay for them. It is to their advantage to
  reduce your ability to know their costs and to
  shop around and see what their competitors are
  charging.
• The Internet has changed the nature of an auto
  dealership. Now most new car customers know what
  they want and how much it will cost the dealer
  before they buy the car. Now car dealers have to
  make their money where the customer lacks
  knowledge, on trade-in values, used cars, and the
  service and parts departments.

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Brokers are hurting

• A broker is in the business of bringing buyers
  and sellers together. Where there are efficient
  communications that allow buyers and sellers to
  find each other without brokers, brokers have to
  become much more efficient to survive.
• Travel agencies are in trouble, because most
  airline tickets are now sold direct. Since the
  airlines no longer need the agencies, they have
  reduced or eliminated commissions.

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And your point is?

• Newspapers are threatened by the Internet.
  Craigs List alone probably reduces newspaper
  classified ad revenues by 50 million a year.
• All of these are examples of disintermediation.
  If disintermediation is a large part of the
  benefit of automation, shouldnt designers think
  about it every time they design a system?

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Goal driven systems

• A best practice in software development is to
  focus on stakeholder goals instead of the
  functions or activities to be performed by a
  system.
• In essence, focusing on goals allows us to avoid
  reproducing functions that are not necessary to
  reach those goals. (More disintermediation!)

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What goals?

• There are three basic types of customers in the
  economy.
• Business
• Consumers
• Government
• Each type has different goals.

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Business Goals

• Business has the following goals
• More Profit
• Lower Costs
• Growth (in size, value, market share, pricing
  power)
• Reduction in competition (buy them or drive them
  out of business)

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Consumer Goals

• Consumers want
• Economy (lower prices)
• Convenience (less time)
• Reliability (no hassles)
• Status (style and perceived quality)
• Pleasure (sex, drugs, and music?)

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Government goals

• People in power tend to have the primary goal of
  remaining in power.
• While they are happy to pass laws that benefit
  special interests and grant monopolies in return
  for campaign contributions, they are aware that
  the customers of government are business and
  consumers, so they have to meet some business and
  consumer goals if voters hold them accountable.

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Government example

• My water and sewer bill is an example of the
  difference in government. It is the only bill I
  get that does not have a return envelope. The
  town doesnt have to worry about customer
  convenience. If your payment is late, they add a
  fine to your next bill.
• I had a septic system. When the town put in
  sewers, I had to pay a sewer assessment, pay for
  a plumber to hook me up, and then pay every month
  for service. Each of those items cost thousands
  of dollars, and I had no choice unless I wanted
  to sell my house and move to another town.

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Fitness for a purpose

• Software development process is about controlling
  the three basic risks of time (late delivery),
  cost (over budget) and quality (not meeting
  requirements).
• One of the most appropriate definitions of
  quality comes from Philip Crosby quality is
  fitness for a purpose. In other words, quality
  is defined by your goals.

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Case Study - Automobiles

• We have had many great cars in the past. They
  include the Stutz Bearcat, the Austin Boat-tail
  Speedster, the Packard Limousine, the Duisenberg
  Model J, and the Studebaker Golden Hawk. I
  deliberately chose examples from companies that
  are no longer in business. Unfortunately, a
  great company needs more than an occasional great
  product to survive.

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What makes a great car?

• Most of those car models had good styling and
  good technology for their period. But consider
  these examples of quality from the standpoint of
  fitness for a purpose.
• Hyundai and Kia
• The Ford Taurus and Buick Century
• Mercedes and Rolls Royce
• I imagine most people would only think of the
  last group as representing quality.

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Hyundai and Kia

• Kia is very hard to describe as a quality
  product. I once asked a tow truck driver what
  was the worst car on the road and he told me that
  he towed more new Kias than any other new car,
  and there werent many Kias to start with. The
  company went bankrupt and was restarted.
• But these Korean cars have a very definite market
  niche. They offer people who otherwise could
  only afford used cars the opportunity to buy a
  new car. That is fitness for a purpose.

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Previous slide soon obsolete?

• The chairman of Hyundai (which also owns Kia)
  Mong-Koo Chung, is determined to raise the
  quality level of the cars they make. Consumer
  Reports rated the 2004 Hyundai Sonata the most
  reliable car on the road. Hyundai has been
  rising to the top of the J. D. Power initial
  quality survey, although both cars are still near
  the bottom in problems after three years. That
  is also changing, as newer cars age and replace
  the old ones. (Last Laugh, Forbes, April 18,
  2005, pages 98-104)

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Taurus and Century

• These cars have embarrassed more teenage boys
  than any others, as they borrowed the family car
  to go on a date. They are average, very
  ordinary, family cars, with nothing exciting
  about their styling. But precisely because they
  tended to fit the needs of many families, they
  are two of the best selling car models in
  Detroits history.
• That is fitness for a purpose.

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Rolls Royce and Mercedes

• These cars were built to burn money, not gas.
• Mercedes has a high reliability record because
  dealers are trained to replace parts before they
  fail. This results in very high service costs.
• But if your objective is to impress the neighbors
  (or your girlfriend) and demonstrate that you are
  financially well off, these cars were designed to
  be fit for your purpose.

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And your point is?

• If quality is fitness for a purpose, we must
  design systems to meet the goals of the
  stakeholders.
• That is one of the primary reasons why designing
  around functions instead of goals can lead to
  disaster.

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Example of a quality design

• Inventory Case Study

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Case study Inventory

• Inventory is expensive. If your store has
  merchandise that will not be sold today, you need
  to pay rent on a bigger store, you may need to
  maintain an expensive warehouse, you need to tie
  up working capital to finance the goods, and the
  goods deteriorate, get damaged or stolen, and
  become obsolete or go out of style.

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Inventory goals

• Why do stores have inventory?
• They want to make sales, and they have found that
  most customers will go elsewhere rather than
  special ordering merchandise.
• They also want to buy cheap and sell at a profit.
  To do that, they need discounts for buying in
  quantity.

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Traditional Inventory

• Traditional inventory is based on economic order
  quantity (EOQ). That is an approach that
  minimizes financing costs, storage costs,
  shipping costs, reordering costs and lost sales
  from being out of stock while maximizing
  manufacturer discounts.
• In traditional inventory, customers and suppliers
  have opposite goals. Customers want small orders
  and big discounts. Manufacturers want big orders
  and small discounts.

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Fundamental Problems

• In addition to the contention between opposing
  goals of customer and supplier, there are three
  fundamental inventory problems
• Out of stock. If you dont have what the
  customer wants, they go elsewhere.
• Overstock. If you order things that dont sell,
  you may have to sell them at a loss.
• Carrying costs. The costs of owning inventory.

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Goal congruence

• These three problems are actually problems for
  both customer and supplier.
• If you are out of stock, the sale might go not
  only to your competitor, but also to the
  competitor of your supplier.
• If you are overstocked, you are less likely to
  purchase from that supplier in the future.
• If you are carrying inventory, your supplier
  needs to keep an inventory to resupply you.
• In these items, customer and supplier have the
  same goals.

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Effect on system design

• Wal-Mart designed their inventory system around
  giving suppliers daily information on what was
  selling, and gave the suppliers the
  responsibility for restocking. Manufacturers no
  longer had to wait for orders, and could reduce
  their own inventories.
• K-Mart automated the traditional inventory based
  on EOQ.
• The result? K-Mart went bankrupt, and the
  children of Sam Walton became five of the ten
  richest people in the world.

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Review Question

• How does Wal-Marts inventory process involve
  disintermediation?

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Answer

• Obviously, automated reordering reduces work for
  buyers who would otherwise have to place orders
  and salespeople who would take them.
• But there are ripple effects throughout all the
  companies involved. For example, with daily
  sales by store, marketing departments can track
  the effects of advertising, promotions and
  repackaging without hiring analysts to gather the
  data.

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More Best Practices

• (besides disintermediation and focusing on goals)

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Study the problem first

• Another best practice in design is to understand
  the problem before you attempt to design a
  solution.
• By focusing on the problem instead of a solution,
  you are more likely to come up with an elegant
  and innovative solution, and less likely to
  duplicate what already exists. After all, why
  duplicate the existing systemyou already have
  it! Dont pay for it a second time!

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Defer decisions

• A best practice derived from understanding the
  problem is to defer decision making as late as
  possible in the design process.
• The later you make a decision that will affect
  the subsequent direction of the product, the more
  information you will have about the problem
  before you make the decision. That should result
  in a better solution.

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Design Patterns

• When you find classic solutions to common
  problems, use them as templates to reduce errors
  and increase reliability.

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Art, Science, and Engineering

• Art (Craftsmanship) is developing elegant and
  innovative solutions to problems.
• Science is a disciplined approach to discovering
  new information.
• Engineering is applying proven methods to a well
  structured problem.
• Systems analysis is a science. Software
  development is engineering. But system design is
  an art.

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Not Paint by numbers

• There was a time when it was popular to sell
  paintings that consisted of line drawings with
  numbers inside each space, and corresponding
  paint sets where the colors matched the numbers.
  You painted the drawing and you had an original
  artwork. Naturally, the results were awful. It
  was embarrassing to see someone display their
  painting in the living room.
• Museums pay millions for art works by Da Vinci,
  Rembrandt, Van Gogh, and Renoir. They dont
  display paint-by-number paintings.

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And your point is?

• You will not become a good designer by learning
  methods, UML drawings, and cookbook recipes for
  software development.
• Understanding disintermediation, focusing on
  goals, studying the problem before thinking about
  solutions, deferring decisions and seeking
  competitive advantage can help you avoid the
  pitfalls of bad design, but they cannot make you
  a good designer.
• Great design is a combination of creativity,
  inspiration, genius, hard work, and experience.

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Review

• Dont model the current system
• Remember Disintermediation
• Focus on Goals
• Fitness for a Purpose
• Study the Problem before you think about a
  solution
• Defer decisions
• Use good Design Patterns
• Design as an artist, not a mechanic