$11$:$154$

ModelBuilding$3$

$80$

Done

Model building $3-$ homework

A car wash enterprise offers motorcar owners the choice to wash their car, and to clean & vacuum the inside, then to polish tyres. The customers that arrive at the car wash enterprise can be distinguished as:

those that arrive with the intend to wash their cars outside and inside $(70\%$ of arrivals$),$

those that wash only the outside.

Customers arrive with a mean internal arrival time of $3$ minutes. The customer interarrivals follow an exponential distribution. All cars that require washing is first washed outside and if the customers require inside cleaning, they que at a parking space before $2$ vacuum$-$cleaning stations. Washing the outside of the cars takes maximum $5$ minutes and not less than $2,5$ minutes. Mostly $3$ minutes.

Polishing of tyres are done just before exiting of the premises. $80\%$ of wash and vacuum clients also do tyre polishing. Only $30\%$ of wash only customers opt for tyre polishing.

The $2$ vacuum cleaning stations are very manually operated.

One team consists of young adults that do the cleaning. They take usually $5$ minutes, definitely not less than $2,5$ minutes and not more than $5$ minutes for the cleaning operation.

The other washing team consist of retired members of the neighborhood that is working to compliment their SASSA grants, by working at the vacuum station. The service time at this vacuum station has a uniform distribution pattern with a minimum of $4$ minutes and a maximum of $15$ minutes.

The que in front of the vacuum stations, feed the first open vacuum station on the ruling of first come first serve. There is space for only one vehicle at a vacuum station.

The que in front of the vacuum station is on the premises, the que forming before the washing stations ques outside the premises in the street. The que at the tyre polish station is part of the tyre polish station.

Develop a Simio model that will simulate this conceptual model and simulate it for an $8$ hours work day.

Use a single source to create all the entities required for this problem.

Where is the bottleneck in the process? Explain.

How many customers could not be helped during the day?

Submit: Your simulated model. Name your submission starting with your student number.

Rubric: Conceptual Model $4$

Customer Arrivals

Mix

$4$

Routing of Customers

$4$

Parking space requirements

Where is the bottleneck?

$6$

$8$ hours

$4$

$4$