# Bolling Electronics manufactures DVD players for commercial use - Project CrashingProject Crash Example

### Problem Data

It is required to calculate the crash schedule of the activities in order to reduce the time of the project, according to the following data:

- Number of Activities
- 7
- Target Time
- 7
- Time Unit
- Weeks
- Description
**Bolling Electronics manufactures DVD players for commercial use - Project Crashing**Bolling Electronics manufactures DVD players for commercial use. W.Blaker Bolling, president of Bolling Electronics, is contemplating producting DVD players for home use. The activities necessary to build an experimental model and related data are listed in the table. (a) What is the project completion time? (b) Accelerate the project up to 7 weeks (the maximum that can be accelerated) at the lowest cost.- Table of Activities
Activity Immediate Predecessor(s) Normal Time (Weeks) Crash Time (Weeks) Normal Cost ($) Crash Cost ($) A 3 2 1000 1600 B 2 1 2000 2700 C 1 1 300 300 D A 7 3 1300 1600 E B 6 3 850 1000 F C 2 1 4000 5000 G D,E 4 2 1500 2000

## Solution

The following are the calculations and detailed graphs to obtain the **critical path** according to the data provided:

### Step 1: Proyecto con tiempos normales

**Network Diagram**

The following chart shows the project activities, calculated with normal times:

The activities in red represent the critical path.

**Normal Project Time Table**

Activity | Time | Early Start (ES) | Early Finish (EF) | Late Start (LS) | Late Finish (LF) | Slack (S) |
---|---|---|---|---|---|---|

A | 3 | 0 | 3 | 0 | 3 | 0 |

B | 2 | 0 | 2 | 2 | 4 | 2 |

C | 1 | 0 | 1 | 11 | 12 | 11 |

D | 7 | 3 | 10 | 3 | 10 | 0 |

E | 6 | 2 | 8 | 4 | 10 | 2 |

F | 2 | 1 | 3 | 12 | 14 | 11 |

G | 4 | 10 | 14 | 10 | 14 | 0 |

The critical path of the project is: **A → D → G**

The total time of the project (with normal times) is **14 Weeks**

Since the project is required to be completed within **7 Weeks**, some activities must be crashed to meet the goal. The procedure will be detailed in the next step.

## Learn with step-by-step explanations

At PM Calculators we strive to help you overcome those tricky subjects in an easier way.

### Membership

With access to our membership you will have access to 13 applications to learn projects, linear programming, statistics, among others.

#### What calculators are included?

Critical Path PERT and CPM

Linear Programming Methods

Normal Distribution

Break-even and more

Purchase our monthly subscription from

Learn more and save with semi-annual, annual and lifetime plans.