Development cost
Operational cost
Tangible benefits
Intangible benefit
One time cost bevore implementation (salaries, hardware)
Recurring expenses(user training)
Quantifiable gains( increased sales)
Non-quantifiable improvments ( brand rep)
Cost benefit analysis
Net benefit
Benefit cost ratio
BCR > 1 meaning
compares total expected costs versus total expected benefits
Net benefit = total benfit - total costs
Total benefits / total costs
BCR > 1 suggest project is financially viable
Break even point
Fixed Cost / (price per Unit - variable cost per unit)
Net present value
What does negative and positive value suggest
NPV = sum from i=1 to n (benefits - costs) / (1+r)^t
r = discount rate
t = time periods(years)
negative = still recovering investment
positive = project profitable
ROI formula
Total benefits - total cost
——————————————- X 100
Total Costs
F-T graph
F0? F1? F2?
Functionality needs to increase over time
F0 = break-even point
F1- optimal point
F2 = decline
Project management techniques
quality assurance
Quality controll
Critical path method
TQM
Feasibility and selection
is project feasible in terms of cost versus beneftis
Technoligically feasible
Organzational capability
impact of risk formula?
likelihood x consequuence
PERT( Progrma evaluation and review technique) - estimates of task duration
formula for t
standard deviation
variance
total uncertainty for whole project
t = (a + 4m + b) / 6
a = shortest time expected
m = most likely time
b = worst possible time
s.d = (b-a)/6
variance = ((b - a ) / 6)^2
add up variances for each activity
Z score
total s.d
AON (activity on network)
- identify activities
- Draw boxes (arrows filled in)
duration = person weeks divided by max staff
Early start = (ES + Duration of all preceding task) start is 0
Late start = min(LS of follwing task(s) - Duration)
Gotta add early start , late start and duration around boxes
early start is top left, late start is bottom left, duration is top right
Critical path
Task which latest start time = earliest start time
GNatt chart
Calculate effort
reschedule so that a maximum of 2 people are
working on the project
max staff goes in each box
ADd Float slack = LS - ES to task NOT ON CRITICAL PATH
effort = people x time
25 person weeks
* 2 people
* 25/2 = 12.5 weeks minimum
13 weeks
13 – 9 = 4 weeks extra
i.e. add 4 weeks float to each task
Determine progress formulas
Expected complete- how we should be doing at this point in time
Percentage complete - how we are doing
EC = (Time spent So Far/ Original Estimate) * 100
PC =(TimeSpentSoFar/ TimeSpent + TimeRemaining) * 100
AOA (activity on arrow)
Uses circles instead of squares
Human preconceptions
Common texture labels, Use of colors, Visual Acuity
Time - users have low tolerance for slow sites
Memory- tend to forget things if we learn them but dont use them
Fonts
Familiarairty
Contetual help(tooltips)
Anthropomorphic approach
design UI to possess qualities human will understand
Sound, niches …
Cognitive approach
Considers the abilities of the human brain - metaphors, logical layouts
Jakobs law
law of familiarity- reuse elements they already understand
Principle of least effort
Humands choose path of least resistance
Fitts law
the idea that the time necessary to move to a target is proportional to the distance and target size.
-make common targets bigger
-minimize distance travelled(mouse routes)
Hicks Law
Reaction time decreases as number of options increase.
So minimize the choice being made on a given ui
UI testing
Empirical approach- task performance, direct observation, recording
A/B Testing- give each tester 1 of 2 designs, see which leads to best results
Multivariate testing- combine and serve parts of a page and see how well they do
