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					                               KOLEJ KEJURUTERAAN
                                  SEMESTER KEDUA
                               TAHUN AKADEMIK 2004/2005

 PROGRAM                   : BE Hons . Mechanical Engineering
 PROGRAM

 MATAPELAJARAN             : Industrial Engineering
 SUBJECT

 KOD MATAPELAJARAN : MEFB443
 SUBJECT CODE

 TARIKH                    :
 DATE

 MASA                      : Three (3) hours
 TIME

__________________________________________________________________________
 Instructions to candidates:


 1. Answer all questions

 2. Questions marks are individually assigned

 3. There are total six questions in this paper

 4. Total marks are 100


 DO NOT OPEN THIS QUESTION PAPER UNTIL YOU ARE INSTRUCTED TO DO SO


 THIS QUESTION PAPER CONSISTS OF SEVEN PRINTED PAGES INCLUDING
 THIS PAGE.
                                                                                2

Q1. Refer below to bill of material for product A. If there are 2
units of B, 1 units of F, and 3 units of G in inventory, how many
units of G, E, and D must be purchased to produce 5 units of
product A.


                                       A
                                       LT = 1

                            B(3)                  C(1)
                              LT = 2                LT = 3

                     D(1)       E(2)       F(1)      D(1)
                       LT = 3     LT = 6     LT = 1     LT = 3

                                           G(1)
                                             LT = 3

                                                                         [20]

Q2.   A   firm uses a continuous review             system and operates 52
weeks per year. One of the items handled has the following
characteristics.

          Demand (D) = 20,000 units/year
          Ordering cost (8) = $40/order
          Holding cost (H) = $2/unit/year
          Lead time (L) = 2 weeks
          Cycle-service level = 95 percent


Demand is normally distributed, with a standard deviation of
weekly demand of 100 units.

Current on-hand inventory is 1,040 units, with no scheduled
receipts and no backorders.
                                                                                       3

   a. Calculate the item's EOQ. What is the average time, in
       weeks, between orders?
   b. Find the safety stock and reorder point that provide a 95
       percent cycle-service level.
   c. For these policies, what are the annual costs of (i) holding
       the cycle inventory and (ii) placing orders?
   d. A withdrawal of 15 units just occurred. Is it time to
       reorder? If so, how much should be ordered?

                                                                                [20]
Q3. The Trim-Look Company makes several lines of skirts, dresses,
 and    sport     coats.   Recently,     a    consultant   suggested    that     the
 company    reevaluate     its   South       Islander   line   and   allocate    its
 resources to products that would maximize contribution to profits
 and to overhead. Each product requires the same polyester fabric
 and must pass through the cutting and sewing departments. The
 following data were collected for the study:




   The cutting department has 100 hours of capacity, sewing has
 180 hours of capacity, and 60 yards of material are available.
 Each skirt contributes $5 to profits and overhead; each dress,
 $17; and each sport coat, $30


       a. Specify the objective function and constraints for this
       problem.


 From the computer solution given below answer the followings:
                                                                                                       4



      b. How much would you be willing to pay for an extra
      hour of cutting time? For an extra hour of sewing time? For an
      extra yard of material? Explain your.
      c. Determine the range of right-hand-side values over which
  the shadow price would be valid for the cut- ting constraint
  and for the material constraint.


                                                         Solution

                      Variable       Variable         Original      Coefficient
                        Label          Value        Coefficient     Sensitivity

                           X1          0.0000           5.0000               2.50
                           X2         20.0000          17.0000               0.00
                           X3         10.0000          30.0000               0.00

                  Constraint          Original         Slack or           Shadow
                      Label              RHV           Surplus              Price

                       cutting            100                  0           4.7500
                       sew ing            180                 40                0
                      material             60                  0           2.7500

                  Objective Function Value:                                640.00



                                         Sensitivity Analysis and Ranges

                                           Objective Function Coefficients

                      Variable         Low er         Original            Upper
                        Label           Limit       Coefficient            Limit

                           X1        No Limit                5               7.5
                           X2             7.5               17              22.5
                           X3    22.66666667                30                68

                                                 Right-Hand-Side Values

                  Constraint           Low er          Original           Upper
                      Label             Limit            Value             Limit

                       cutting            60               100            132
                       sew ing           140               180       No Limit
                      material   33.33333333                60            100

                                                                                                [20]

Q4.    Dixie   Bank     in       Dothan,         Alabama,           recently        installed   a   new
automatic teller machine to perform the standard banking services
                                                                                5

and handle loan applications and investment transactions. The new
machine is a bit complicated to use, so management is interested
in tracking its past use and projecting its future use. Additional
machines may be needed if projected use is high enough.


At the end of April, the average monthly use was 600 customers and
the trend was +60 customers per month. The actual use figures for
May, June, and July are 680, 710, and 790 respectively. Use trend-
adjusted   exponential   smoothing   with   a   =   0.3   and      =   0.2    to
forecast usage for June, July, and August.
                                                                         [10]
Q5. Consider the following project information




      a. Draw the network diagram for this project.
      b. Specify the critical path.
      c. Calculate the total slack for activities A and D.
      d. What happens to the slack for D if A takes five
      weeks?
                                                                        [20]
Q6.   Multiple choice and T/F
i)    An MRP system provides which of the following advantages?
                                                                     6

      a.   Automatic update of the dependent demand and
           replenishment schedules of components when parent
           schedules change
      b.   Statistical forecast of component demand
      c.   Smoothing of lumpy demand
      d.   None of the above
ii)   The key inputs to an MRP include:
      a.   engineering drawing of the product.
      b.   process chart.
      c.   inventory record database.
      d.   both a and b.


iii) If gross requirements are 100, planned receipts are 120, and
inventory on hand from the previous period is 50, then the
projected on-hand inventory balance:
      a.   is 270.
      b.   is 170.
      c.   is 70.
      d.   cannot be determined from the data given.


iv) The portion of total inventory that varies directly with lot
size is called safety inventory. (T/F)


v) The average cycle inventory is the average of two extremes, the
maximum order size and minimum order size (zero). (T/F)


vi)During periods of uncertain demand, the reorder point (R)
equals demand during lead time. (T/F)


vii)Safety stock size is a trade-off between customer service
(availability) and inventory holding costs. (T/F)
                                                                     7

viii) If lead time increases but average demand for the item per
period does not, the pipeline inventory will not increase. (T/F)


ix) A sample statistic that falls between the UCL and the LCL, but
not on the nominal value line when plotted on a control chart,
indicates that the process is exhibiting assignable causes of
variation. (T/F)


x) The analysis tool for a quality problem that involves selecting
the problem, identifying the major categories of potential causes,
and associating likely specific causes is:


a.   Pareto charts.
b.   fishbone diagrams.
c.   scatter diagrams.
d.   checklists.
                                                       [1 each=10]

				
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