Question

The following jobs are waiting to be processed at Rick? Solano's machine center.? Solano's machine center has a relatively long backlog and sets a fresh schedule every 2? weeks, which does not disturb earlier schedules. Below are the jobs to be scheduled? today, which is day 241 ?(day 241 is a work? day). Job names refer to names of clients and contract numbers. Compute all times based on initiating work on day 241.

(Job) (Date Job Received) (Due Date Duration (days))

BR-02 225 270 25

CX-01 230 320 35

DE-06 235 360 40

RG-05 231 310 30

SY-11 228 300 15

Using the LPT? (longest processing? time) decision rule for sequencing the? jobs, the order is? (to resolve a? tie, use the order in which the jobs were? received):

The average tardiness? (job lateness) for the sequence developed using the LPT rule? =

The percentage utilization for the sequence developed using the LPT rule? =

The average completion time for the sequence developed using the LPT rule? =

The average number of jobs in the system for the sequence developed using the LPT rule? =

Critical Ratio? (CR) for each job is given by the? relationship:= (Due Date-Date Today) / (Processing Time). what is CR for jobs a-e

.

Using the Critical Ratio? (CR) scheduling rule for sequencing the? jobs, the order? is:

.

Answer 1

Scheduling as per LPT rule -

Job	Date received	Process time	Due date	Order	Flow time	End time	Lateness
DE-06	235	40	360	1	40	280	0
CX-01	230	35	320	2	75	315	0
RG-05	231	30	310	3	105	345	35
BR-02	225	25	270	4	130	370	100
SY-11	228	15	300	5	145	385	85
TOTAL		145			495	1695	220
AVERAGE					99	339	44

Average tardiness = 44

Utilization = 145/495 = 29.29%

Average completion time = 339

Average jobs in the system = 495/145 = 3.41

Scheduling as per the Critical Ratio -

Job	Date received	Process time	Due date	Critical ratio	Order
BR-02	225	25	270	1.16	1
CX-01	230	35	320	2.26	2
RG-05	231	30	310	2.30	3
DE-06	235	40	360	2.98	4
SY-11	228	15	300	3.93	5